The Stovebolt Site Forums The Shop Area Engine Shop Increasing performance

We’ve got a 1946 gmc EC152 with a factory 228 in it. What can I do to get a little more performance out of it? Has anyone bored one out? We’ve rebuilt the carb, adjusted the valves, etc. it idles great, but seems to bog down a bit when you really ask it. Any help or ideas would be appreciated.

I had my 235 bored .030 over and put a cam in it. Also got a better intake and headers. It made a noticeable difference in performance.

Sorry, big $$$ gains little power

Cheap and easy. Won't gain a lot but it costs nothing. If you're timed to stock specs, those specs were set for about 65 octane gas. Leave your timing light in the drawer. Warm your truck up then time to fastest/smoothest idle and lock it down. Re set your idle then take it for a spin. If it doesn't ping under load or drag the starter you're good to go. You should be able to advance your timing at least 10 degrees. It made a noticeable difference in my 38.

"There's no replacement for displacement". All the GMC sixes are pretty much bolt-in swaps. Find a 248, 270, or 302 to swap for the 228. GMC engines are scarce and expensive to modify, since most of them were used, abused, and and destroyed back in the 1950's and 60's by dirt track racers, drag racers, and Bonneville land speed record runs. The days of having thousands of WW II military surplus 270's and a few military 302's from the 1950's are distant memories. There's a small group of hard core GMC hotrodders still out there, but it's a pretty exclusive bunch.

Chevy 235 and 261 sixes are much more common, less expensive, and they share the same bell housing bolt pattern and a lot of other bits and pieces with the GMC's. The "go fast" parts for Chevy engines are also a lot less pricey than the same stuff for GMC engines.
Jerry