Mailbag: Finding More Power for Already-Upgraded ’95 GMC Sierra

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Q. My daily driver is a 1995 GMC Sierra C1500. It has a 350 TBI engine matted to a 4L60E transmission with a TCI Sizzler torque converter, a 10-bolt 8.5-inch posi rear end, and 3.08 gears. The entire setup has been absolutely bulletproof.

I’ve added a free-flowing exhaust, ACCEL plugs, Taylor 8mm wires, an MSD Blaster coil, an Edelbrock Performer intake, a Trans-Dapt TBI spacer, and a 14-inch Edelbrock air cleaner.

My question is: What else can I do? Can I change rear gears? What about cylinder heads? Also, would factory injectors from a 454 SS be too much for my 350?

A. It sounds to us like you’re on the right track. With a computer-controlled truck like yours, it might seem like the list of available performance adders is pretty short, but there are a few tricks left that can net you the extra grunt you’re looking for.

By adding a little more gear in the rear end, you’ll get a nice boost in acceleration, and a little off-the-line power. A 3.73 ratio set from Richmond Gear (RMG-4900411) should yield the perfect combination of acceleration and fuel economy for your daily driver.

With the rear end taken care of, turn you attention up front with a pair of Edelbrock Performer assembled aluminum cylinder heads (EDL-60859)—they’re CNC-machined for optimum flow, and that means improved throttle response and increased horsepower throughout the rpm range. And those big block injectors are a great idea. They’ll pony up the fuel necessary to get the most out of this setup.

Finally, bring it all together with a Motorvation custom chip to program your truck’s ECM to compensate for the bigger injectors and higher gear ratio.

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One Comment

  1. David Shull says:

    If you are going to be replacing cylinder heads and a custom chip…might as well upgrade the camshaft and go with roller rockers (may need taller valve covers too) while you are tearing the engine down that far.

    Give the folks at Summit Racing a call, they will be happy to recommend the right camshaft for how you will be using your vehicle.

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