LS Engines

LM7 5.3L Engine Upgrade Guide: Expert Advice for LM7 Mods to Maximize Performance

[Editor’s Note: This LM7 engine upgrade guide is part of a series of LS engine upgrade guides assembled by a team of LS experts at Summit Racing that we are sharing at OnAllCylinders. For a primer on the entire LS engine universe, read LS Engines 101: An Introductory Overview of the Gen III/IV LS Engine Family.]

Intro to LM7 Engines

Meet the hidden gem that helped start the LS-swap craze.

The LM7 (along with its L59 FlexFuel E85-capable brother) are the Gen. III, 5.3L iron block truck engines you can pick up in wrecking yards for about $600.

There were a couple key areas where the LM7 excelled:

1. It makes sense for engine swaps.

Fully dressed, it’s a bit lighter than Gen. I/II engines and easier to find one in good shape. Even bottled up and 25 cubic inches smaller, it matched the power and torque of the F-body LT-1’s. The later 2004-07 versions were right there with the C4 Corvette’s LT1. With the availability of engine swap kits, it just makes good sense to use Gen. III/IV engines.

2. Drag racing.

The aluminum blocks made good power naturally aspirated, but they aren’t the best choice with big boost and nitrous. Although the iron block LM7 is a bit heavier, you can really pour the coals to it. Because of their strength, these engines are likely to see a power-adder sooner than later.

[Every engine spec you’ll need can be found here: LM7 5.3L Vortec 5300 Engine Specs: Performance, Bore & Stroke, Cylinder Heads, Cam Specs & More.]


How to Get More Power From Your LM7

These engines started life in GM trucks, but there’s just as much of a chance today that you’ll spot them under the hood of a turbocharged drag car.

This article is focused on the power-adder pathway for upgrading the LM7, whether it will remain in a truck or be swapped into a car.

The LM7 is one of the most popular LS engines for several reasons:

  • With iron block strength, it is a great choice for boost or nitrous applications.
  • GM made a bazillion of them over eight years. The abundance of LM7 engines available helps keep prices down.
  • Gen. 3 engines didn’t have AFM (Active Fuel Management) or VVT (Variable Valve Timing), so you don’t have the expense of an AFM or VVT delete kit.
  • The heads flow similarly to LS6 heads, but have a boost-friendly 9.5:1 compression ratio.

Do they have a downside? Just one. At 216 pounds, the block is 100 lbs. heavier than the aluminum LS1 block.

Basic Bolt-On Upgrades for LM7 Engines

Trucks are the everyday hotrods of the 21st century.

Many people start off adding a cold air intake and aftermarket exhaust.

The problem is that the engine starts to sound REALLY good and owners find themselves wanting to go faster.

Trucks often come with mechanical fans that sap horsepower. An electric fan kit will free up the power. All these can be done in the garage, but the tune won’t be optimized.

At this point, we recommend you talk to your chassis dyno tuner and decide on a computer programmer. Whether you’re towing on low-octane or springing for good fuel, a tuner can dial-in the ECM and take it to the next level.

Shift points can be raised which also makes it easier tune for a bigger cam and injectors later. Additionally, installing a colder thermostat will open up the tuning window.

Below are more upgrades that will improve LM7 engine performance.

Upgrading the LM7 Camshaft and Valvetrain

If you only do one thing to the engine, make it a cam swap.

The tiny 191 at .050-inch cam really held these engines back.

An LS3 or LS9 cam makes good power, but not where you want it, if the engine remains in a truck.

What you need is a cam that delivers a gut-punch right where the converter hits. We recommend a dedicated truck cam.

If the engine is going in a lighter car with gear and converter, you can be more aggressive.

What’s the difference between a truck cam and car cam?

GM LM7 camshaft

To maximize torque in the mid-range in a truck cam, manufacturers close the intake valve at about 40 degrees (@.050 in.) after bottom dead center and alter the intake valve opening to set the idle quality.

The bigger the engine, the smoother it will idle for any given cam, which is why you’ll see the 5.3L LM7 getting slightly smaller cams than the 6.0L engines.

What if you have a power adder? 

Generally, supercharger cams and nitrous cams will have slightly more lobe separation and longer exhaust duration. Turbo cams reduce overlap with less exhaust duration in relation to the intake.

Intake Duration (@ 0.050 in.)Horsepower at the wheels after bolt-onsIdle QualityNotes
191° (Stock)260-270 whpSmoothHeavy drivetrain.
215°+50 hpSlightly noticeableGood with auto and stock converter.
220° - 230°+75 hpSteady lopeConverter recommended. Still can drive daily.
230° - 240°+100 hpLopeyFly-cutting the pistons may be required. Heads and intake good for another 50+ hp.

Drop-in .500-in. lift cams are popular, but LS6 springs allow you to run .550-in. lift and extend the rpm range. Spring life isn’t a problem because trucks generally don’t spend a lot of time at high rpm.

Beyond that, .575 to .600 in. isn’t a problem with dual valve springs.

The stock rockers are good up to 175 lbs. of seat pressure and 450 lbs. open. You will want to install a trunnion kit for added reliability.

There are a few other parts needed for a LM7 cam swap such as an LS2 timing chain, LS7 spec lifters, LS2 timing chain damper and adapter, as well as .080 in. wall pushrods.

LM7 Power Adders

In general, most LM7 owners will add boost or nitrous before they begin serious cylinder head work. Before we get into the power adders, there are a couple of things to address.

1. A 4-corner steam kit reduces hot spots that can cause the piston rings to butt and snap the piston’s ring lands.

2. Any power will put you well past the limitations of the stock injectors and fuel pump. We’ll address those in the next section.

Now for the fun stuff:

  • nitrous oxide kit (at low settings) is great for street driving with stock internals. Up to a 200-shot system is common. Keep in mind the tight piston ring gap is the limiting factor beyond that. If you want to get serious, a single-plane intake is less prone to break from a nitrous backfire. A plate system has better distribution than the original intake, but an eight-nozzle fogger system is even better. Running higher-octane fuel is advised.
  • Truck engine bays make fitting turbos easy. Single turbo systems using turbo exhaust manifolds are an inexpensive way to make big power. If you’re running a single turbo, the T4 hot-side fits well, but the small-turbine diameters limit exhaust flow. The 650 whp begins to feel like 400 did in a hurry, so take this into consideration. V-band style exhaust housings open up the turbine options and make plumbing easier. Although twins are a little more expensive out of the box, you’ll have more room to grow.
  • roots-style supercharger is dependable and makes great torque in the low- and mid-rpm range. It’s great for melting tires.
  • centrifugal-style supercharger is lightweight and makes more power at high rpm. This is partially due to a larger intercooler mounted in front of the radiator.

Upgrading the LM7 Fuel System and Tuning

The factory LM7 injectors were only rated at 22-25 lbs. and won’t support much more than 380 hp.

Plan on upgrading to larger fuel injectors to meet the fuel demands of increased power.

Custom tuning will be required to properly adjust the fuel and ignition timing. Truck manifolds had 1.9-in. injectors versus the longer Gen. III car injectors or the shorter Gen. IV injectors. The connectors are different as well, but adapters and spacers can be used to fit car injectors on an LM7.

Keep in mind, the best injectors are fully characterized which helps your tuner maximize idle quality, etc.

When running boost, you can use a water-methanol system to supply extra fuel and lower-charge air temps.

The factory pump is good to about 430 whp. Many fuel system upgrade options are available. Drop-in fuel pump modules and external pumps are popular. Other options to maintain or increase pump pressure include electronic voltage controllers and hotwire kits.

Upgrading the LM7 Intake Manifold and Throttle Body

If you have a power adder, the intake and throttle body can take a backseat for a while longer. If you are naturally aspirated though, upgrading the intake and throttle body is commonly done before the heads.

The factory truck-style manifold has long runners for better low-end torque. Porting the intake is an option and a good value.

If you’re looking for more power and torque, the Trailblazer SS intake is a step up and a larger 90mm 4-bolt throttle body can be fitted.

The F.A.S.T. LSXRT intake allows a bigger 102mm+ throttle body. Truck engine bays also accommodate Tunnel Rams. These trade a little bit of torque down low for more up high—and nothing looks cooler.

Manifold StylePeak HorsepowerTorque
Single Plane+10 hpLosses everywhere below 5500 rpm. *Only recommended for nitrous or boost.
Trailblazer SS+10 hpMaintains torque and pulls ahead at 4500 rpm.
F.A.S.T. LSXRT+25 hpMore low-end and top-end.
Tunnel Ram+35 hpSlightly lower below 3000, equal at 4500, and big gains beyond 5500.

Ask your tuner about going with a Speed Density tune. Doing so removes the MAF restriction and will give you a bit more power.

[Trying to find an LS or LS-based Vortec engine for a swap or build? Check out Part 1 and Part 2 of our LS Spotter’s Guide.]

Upgrading LM7 Cylinder Heads

  • The stock heads can be CNC ported for more airflow and milled up to .030 in. for more compression. Flow numbers can be as high as 325 cfm at .600 lift. Lightweight hollow stem LS3 valves can be cut to 2.000 in. to fit the seats. Between the light valves and better springs, the engines will pull cleanly to 7000 rpm. Keep in mind, if you’re looking to boost to 800+ hp; a heavy duty aftermarket stainless intake valve is a bit tougher and won’t tulip as quickly with the heat.
  • A better option is aftermarket cathedral port heads. They reduce down-time, they’re all new, and you can usually offset the added cost by selling your original heads. Valve angles are typically laid over to 13.5 degrees and 2.040-in. intake valves are common. They flow great and the cross-sections are great for boost. When comparing heads, look at .400 lift numbers as a general indicator of how the heads will perform. With a medium-sized cam, 400+ whp naturally aspirated is common even with the heavier truck drivetrain.

Upgrading the LM7 Rotating Assembly

Still looking for more?

As mentioned before, the pistons are a weak point and you probably know a guy that’s popped one. A set of forged pistons should be high on your priority list. They have stronger wristpins, thicker ring lands, and the added valve reliefs allow you to run big cams. If you’re going over 800 horsepower, a set of .200 wall tool-steel pins is a good idea.

There are exceptions, but Gen. III rods start getting dicey around 750 whp and the bolts don’t like much more than 7,000 rpm. The 2004½-07 modes were bushed for full-floating pins and were stronger. If you’re getting forged pistons, it’s best to also get forged connecting rods with 7/16-in. rod bolts.

The LM7 crank was cast but strong. They’ve been known to handle over 1,000 whp. The main reason for going with a stroker forged crank is for the added cubic inches. The extra cubes bring boost on quicker which means you can use bigger turbos.

GM LM7 engine

Performance rotating assemblies are available in many combinations.

Notes of caution:

  • The 5.3L iron blocks had shorter cylinder sleeves than the aluminum blocks (5.430 in.  vs. 5.500 in., on average). Much of the piston skirt drops out of the bottom of the cylinder at BDC. The best piston manufacturers have compensated for this by eliminating skirt taper until a point well above where it meets the bottom of the cylinder sleeve at BDC. Any skirt taper at this intersection acts as a razor blade and will wear out the piston quickly.
  • The blueprint deck height of the block is 9.240 in., but it’s common to find them in the 9.230-in. range. It’s best to measure deck height before ordering your rotating assembly. Thicker head gaskets or using an aftermarket 6.098- to 6.100-in. rod will ensure enough piston-to-head clearance.
Engine SizeBore Dia.Piston Comp. HeightStrokeRod LengthWristpin Dia.
(325 c.i.d. - stock)
3.780 in.1.338 in.3.622 in.6.098 in.0.9431-.09449 in.
(347 c.i.d.)
3.905 in.1.338 in.3.622 in.6.098 in.0.9431-.09449 in.
(363 c.i.d.)
3.800 in.1.115 in.4.000 in.6.125 in.0.927 in.
(383 c.i.d.)
3.905 in.1.338 in.4.000 in.6.125 in.0.927 in.

Upgrading the LM7 Engine Block

The 5.3L iron blocks can be bored to the LS1’s size.

If you’re running boost and nitrous, most will just hone the blocks to 3.800-in. or up depending on piston and ring availability.

The blocks have been known to withstand 1,300 whp with proper machining, racing fuel, and an excellent tune.

Head and main studs are advised if you’re making more than 850 whp. Four head bolts per cylinder aren’t optimal, but you can O-ring the block if you’re aiming for 1000+ whp.

The factory main caps aren’t doweled. It’s better to reduce ignition timing and compensate with added boost to reduce the cylinder pressure spikes that lift heads and cause the main caps to dance.

(Information for this article originally appeared in the “Upgrading the Gen. 3, 5.3L, Iron Block, LS Truck Engines” article at Summit Racing’s searchable database of FAQ tech infoGo there and search “LS engines” for a comprehensive collection of LS engine tech information.)

NOTE: You can find engine specs and detailed engine upgrade advice for every LS and LS-based Vortec truck engine in one place: The Definitive Guide to LS Engine Specs and LS Engine Upgrades.

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  1. Pingback: LS Engines 101: An Introductory Overview of the Gen III/IV LS Engine Family - OnAllCylinders

  2. cassidy wright says:

    i have a 2004 Chevy Silverado Z71 1500 with the LM7, i have done the Airraid M.I.T. tube upgrade with a K&N filter on the stock box. i have not yet done an exhaust. would upgrading to a 90mm throttle body on the stock intake manifold make sense or not? i have a Diablosport i1000 tuner and was wondering if anyone knew what settings i should be running on it for maximum hp on 91 octane pump gas. also at what point does it make sense to upgrade my ignition system?

  3. Brian Nutter says:

    Cassidy, you could adapt a 90mm TB to the factory intake, but the 2008ish + intakes perform better and have a larger opening. They were patterned after the TBSS intake. I wouldn’t do that until later because it’s not much of a restriction. Going with a true dual exhaust is a plus. The ignition won’t require any changes. Best bang for the buck out of everything is a cam swap to one of the Summit Pro LS Stage 1 truck cams. There are three. One tow cam, one drop in cam for stock springs. Then a .550 lift version for use with LS6 springs.

  4. hello I have a tahoe lm7 engine 2005 casting number 12551358, I will use it to drift in a 240sx that cams would recommend me and what springs for more power

  5. Gary Solesbee says:

    I have a ‘99 LM7 with 90,000 miles that I plan on installing in an ‘80 Mazda Rx7. I don’t want to get too radical but I would like a small cam to give it a little lope. It should have plenty of power stock as the car is light at 2300 lbs. Any suggestions? Thanks, Gary

  6. 68Firebird says:

    find the Comp Cam 54-700-11, IMO is the best cam for the LM7 LQ4 engins. You don’t need push rods/springs. It just slides in. I have the LM7 in my 68 firebird with LS6 intake, 92mm TB, mid-headers, true dual exhaust. going for the DYNO this weekend. Hopeing for close 400hs, maybe 375 to the wheel.

  7. Connor Macintyre says:

    Hi, I’m looking at putting in the TSP Stage 4 5.3 cam (223/226 .600/.600) with all lifters, springs and push rods as well as the ls2 timing chain. for Air/Fuel i’m going to do a ls6 intake with 36psi injectors. i was going to switch to 243 heads and flattop pistons to bring the compression back up. I’m just wondering if this would be a solid build?

  8. Jason Wysong says:

    What Cam is recommended for the lm7, Installed in an OBS 4×4 and using the manual transmission?

    • Scott Long says:

      Jayson Wyson – Brian Tooley Racing Stage 3 truck cam w/ LS6 springs would give a good jump in power and have a nice little lope at idle. Being a manual you don’t have to worry about changing torque converter. You could probably even run a Stage 4 cam.

  9. Hi Brian,

    My 2005 GMC Yukon, 5.3L LM7 engine has 178,000 and has had an engine ticking problem for some years now. A mechanic told me that it needs a cam and/or lifter job. The ticking comes and goes, but the engine has noticeably reduced power from when it was new. We had this car since it was new.

    I don’t want any mods, I just want to restore it to the way it used to be.

    What do you recommend doing, and do you know of any reputable shops in Brooklyn, NY to take it to (or a reasonably distance away?)



  10. Jim Boldenow says:


  11. so I have my lm7 in the shop getting worked over. it was a stock lm7. but now my guy has bored it to 5.7 liter with flat top pistons. with 706 heads, I’ve hard that they are not to desirable. but they are 61.17 cc. that’s low in my book. my guy is gonna put the biggest intake valve in there and work those chambers around. I need 10.5 to 1 to make my trick flow cam to work. it’s a .585/.585 228/230 112. my question is why are the 706 not desired heads? I have a velocity intake with 78lbs injectors 102mm tbody with long tube headers. along with a walbro 400 fuel pump. the tranny is a 4l60e I have a 2400 stall and shift kit, along with the corvette servo upgrade. I want 373 posi I just haven gotten that rear end stuff yet. but it is a stock 8.4 rear end. it’s a 2003 gmc short bed serria. does it sound like im on tbe right path with my build. this is my first ls1 build. ive built alot of engines and cars. but this is my first motor this big. my machine shop guy is gonna put the engine together for me. I’ll just have to hook everything up I am sending my com to pcmforless for the retune to get the engine started. I plan on a dyno chassis tune. when I get my lil black truck going. so what you guys think about it and please be honest. it’s been about 5 months in planning this out and about 6,000.00 including buying the truck

  12. Hi folks,
    I had an Atk HP97 installed in a 2006, crew cab , tow z71 package, rear diff 342 to 1, what would be my next up grade? Mid length headers, stock air box and k&n filter, magna flow exhaust! CPU tuned by computer modulation, ride along flashing, high volume oil pump! Quoted 385 pluses horse power and 390 pluse torque, think it’s over 400 for both!

    • Hey Brian I have got the hp97 lm7 also.who tuned the engine for you I really need a tune I just put the engine in. It’s runs but not a stable idle and need a tune.

      • Travis Leach says:

        What other mods were required? Its obvious the upgraded engine had the afm/dod deleted, I have the same engine on order waiting for shipment in the next 5 weeks or so. I’ve heard the valley cover needs to be different and can’t use the stock on?

  13. Hey there
    2001 Tahoe LT. Bone stock other than a Super 40 Delta flow muffler and mild tune. 320,000km. But thats just broken in for. 5.3 that has been lady driven since the lot. Im worried only about certain modes at this time in its life that will create lets say issues. Was thinking intake manifold, cold air intake and a possible stage 3 tune? Plugs wires and coils. Just a start to see how it reacts? Any thoughts?

    • I have the same question if someone would be so kind as to answer and/or gives thoughts, opinions and experiences.

  14. Frank Sirago says:

    Can you steer me to a right cam application ,What i have is a 2000 5.3 which I swapped in a 3rd gen camaro ,I want to keep stock converter just looking for a step above stock cam that can deliver noticeable power ,,Be much appreciated

  15. Why does this article say I need to buy LS2 parts (timing gear, damper, etc.) to replace the cam in a an LM7? If I am getting a dedicated LM7 cam it doesn’t seem like u would have to convert anything to LS2 spec. Is this recommended for a specific cam? It’s not very clear.


  17. of course it stops at 2007 when I have a 2008. its hard to find anything on the 2008 model

  18. I have a 2000 gmc 1500 with the 5.3 how much hp do you think I could make with a stage 3 550. 550. Lift 232 232 cam, headers, K&N Intake and cathedral ported heads, a fan upgrade, injectors, fuel pump and a dyno tune

  19. I have a 07 which is a 08 body style GMC Sierra 5.3. I’ve added a tap v2 torquer 232/234 cam with springs, valves, timing chain, etc that come with the cam package. 3200 circle d stall, 430 gears, Eaton possi, traction bars tru cool trans cooler, mad wires, k&n intake, long tube headers, no cats, and magna flow bullet exaughst. What is the next step I need to take before I mess anything up and add power. Yes it’s tuned

  20. Megan R Last says:

    I’m currently building an lm7. I’m considering boring the block but need to know how much of a bore I can put. Looking to also upgrade the cam. How can I know if I have a good combination with the bore & cam? What other parts do I need to upgrade? I have stock 862 heads, can these be used with a bore and cam? Does the crank need to be upgraded? What about the torque converter or injectors? I’m honestly kinda lost and need help. The motor is in a 3/4 ton so it’s backed by the 4l80.

    • bore the block as little as is needed. You don’t get much power from boring. You get more power from Cam and other mods. But you do get thin cylinder walls from boring out. If you can get by with 10 or 20 thousand just bore what you have to to get it true. no point in weakening the engine and preventing future rebuilds if you don’t have to

  21. Thanks for all the reliable information on Lm7’s! Very helpful facts to locate, restore, and build this little gem. Thanks again!

  22. Reinaldo Cruz says:

    we have a stock LM7 5.3L we are making it single turbo, which cam cam we use to reach 600hp and do we need to upgrade lifters and valvetrain??

  23. I have a 2002 LM7 5.3 and I’m looking to swap out my v6 Cutlass. I’m on the rebuild stage now and looking for a Piston/Rod Set and nice Cam shaft. What would you recommend?

  24. Joseph Branham says:

    I’ve got an 05 avalanche and I want to build a 500hp street rod with it.
    What direction would you recommend I do have the LM7 5.3. 2wd. Ju ssd’s t not sure which way is best for endurance. Thanks

  25. hello,
    2007 5.3 flex afm. Want to remove this engine and install a ls 5.3 or 6.0. not looking to fly but a little more power is always good. so, besides the engine, suggestions on cam? crank? programmer and so on. sorry all, i have read and heard so many options. and all the parts dealers dont list parts as groups or by hp increase. and the worst part, i live in california, so yes,
    need pass smog, or will i have to reinstall og engine?

  26. STEVEN D. BETTIS says:

    Great Tech ! Thanks . I’ve got a 2001 Tahoe LS that’s getting a bit Long in the Tooth . Someone nearby has a 6.0L (LQ9) Cam for sale . He makes a statement ” It’ll really wake up your 5.3 ! The swap can’t be that simple , right ? What else would I need to complete springs/timing Set etc. / gaskets/seals/oil pump / water pump , My hoses are starting to weep as well , I’m getting those seen too . At this point what advantage if any would I gain installing a 160* while it’s torn down ?

    • Just my two cents, but why would you go that far to tear everything apart and install a used cam (stock cam for 6.0). Just install a cam that has been dyno proven and will actually work with your 5.3. Texas speed has great cams, BTR….etc. Springs, pushrods, rocker trunnion upgrade, water/oil pump will all be good things to replace and address while your in there. Then you will a custom tune to make the new cam work with your setup. Good luck.

  27. Kevin Silbernagel says:

    I have a 2000 chevy vortec 5.3 that is going in my 54 Willys Pickup. I won’t have much room in front of the engine. Is it possible to rotate the intake manifold 180 degrees so I can suck fresh air from the cabin area?

  28. Pedro T Rodriguez says:

    I have a lm7 off of a 05 Silverado and putting it on my 16 1/2 Polaris slingshot and wanted to know what is the best automatic transmission that I can put it and can handle 450-500 horsepower with out being an electronic trans. haven’t decided to go with turbo or a supercharger to get to the horsepower I want .
    any help will be appreciated thanks for your time and help.

  29. Hello, I have a 2001 Chevy Silverado with the LM7 Vin T. This truck was my dads truck and the oil was changed in it very often not even at 3000 miles using Castrol 10/30. I had 120209 on it and didn’t like the piston slap at cold temp and start up so i had it completely rebuilt and the engine was very clean at tear down.Several things found disturbing me was that ther were 5 of the 8 pistons that was so loose at TDC and the piston rings were almost staggered on many.I have been a GM mechanic for 17 years and this was a great easy rebuild using my skills and the book How to rebuild LS Engines.The only thing i regret is changing the stock camshaft.It looked great with little wear and i replaced everything else in the engine.I went back with new flat top pistons and i have the 862 heads. All machine shop work was done and the rebuild was great.It runs awesome but now i want to put a upgrade on the camshaft. I don’t remember seeing any holes in the block to use the 5/16 rods to hold up the lifters to swap out the camshaft.Can anyone verify if the LM7 has the holes in the block to use the rods to hold the lifters up to replace the camshaft.

    • Yes they do. Just put a Texas speed stage 2 .550/.550 lift in mine. Woke it up big time

      • I love the power that the Texas Speed bump stick added to my 5.3. Dyno tuned the truck and picked up 56 HP. She screams for sure and is a whole new animal!

  30. After watching hot rod garage put an LM7 in a camero , my thoughts of dropping one in my 1988 Chevy suburban 4X4 stick shift keeps me up at night. Being 70 years old, I want EZ and cheap. If you know of a good swap book, please reply. I’m after hassle free good reliable power

  31. Is there a way I can get this info and a catalog so I can order from y’all what combos I need for performance

  32. Jeremy Frederick says:

    Iv got a bone stock 2004 Tahoe LM7 looking for 700+ hp not sure where to start as this will be my first build. And the stock 4L60E I doubt will hold up any advice would be appreciated

  33. Austin McCarrell says:

    Doing a Gen ||| LM7 with 706 heads from a 03 Silverado swap into my 330 BMW. First time doing a motor swap so any info would be appreciated as I think I’m overthinking it. Looking for a choppy cam, info on if I should leave the heads stock or upgrade, whats a good intake to go with, planned on running A/C but no power steering

  34. Sean d Lutzi says:

    for mild boost applications, there is no need to upgrade injectors if the motor was built for E85 at the factory. I;E flex fuel. the injectors are large enough to accept a small turbo or supercharger and supply enough fuel(pressure) to the system.

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