We’ve got the answers—the Summit Racing tech department tackles your automotive-related conundrums. This week, we’re rebuilding a small block Mopar to produce maximum low-end torque:
Q: I am restoring a Dodge M37 military truck. I’m replacing the original 230-cubic-inch straight six with a Chrysler 318 V8 and an NP435 4-speed manual transmission. The new engine and transmission will be mated to the M37’s stock NP201 divorced transfer case and 5.83-geared axles. The tires are 40 inches tall.
I want to rebuild the engine to produce as much low-end torque as possible. I don’t have a lot of money to spend and I’m going to reuse many of the components (pistons, connecting rods, crankshaft, cylinder heads, and so forth). Could you recommend a good cam, intake manifold, carburetor, and electronic ignition system that will improve the low-speed performance of my truck?
W.W. Pinckney, MI
A: Let’s start with the camshaft and intake. For optimum low-end torque and throttle response, you can’t go wrong with an Edelbrock Performer-Plus cam kit, valve springs, and Performer intake manifold. The smooth idling cam in this kit is perfect for dual-purpose trucks. The dyno-matched Performer intake manifold will boost torque from idle to 5,500 rpm.
For maximum performance and fuel economy, ditch the carb and install a Holley Pro-Jection fuel injection system. The 670 cfm, stand-alone fuel injection system uses a specially calibrated ECM to maintain exceptional drivability and fuel control over all types of terrain.
In our opinion, the best ignition on the market for a Chrysler engine is Mopar Performance’s electronic ignition conversion kit. This magnetic impulse ignition system has many advantages over breaker points-type ignition systems—like less frequent tune-ups, increased secondary voltage, improved starting, more precise timing and dwell, and increased spark plug life.