I have a 289 C code engine. Rebuilt with a cam/4v carb and intake. Looking at a chart I found it shows that my motor came with 53cc heads. Right now I’m still running stock heads and I really want to upgrade to aluminum and roller rockers. I’m having a hard time finding a good set of 53cc heads. If I go up to the more common 60cc how much compression will I loose? I know either way I will gain horse power but If I can get more hp out of keep the 53cc combustion chamber then I’m all for that! But seems they are harder to find on sights like summit or jegs.
How will going from 53cc to 60 cc gernerally affect my compression?
Before you start upgrading your engine, have you made any improvements to your brakes or suspension?
Also, 60cc heads will drop the compression from 9.3 to 8.66. That’s pretty low for most performance cams.
stering/ suspension has all been redone. except for leaf springs which i will be doing soon. I just rebuilt front brake calipers last week and will be rebuilding the distribution block/ proportioning valve mot likely this weekend. master cylinder is done. she stops and handles like a new car right now.
A set of used 58cc GT40 heads will run you about 2 bills at a swapmeet and you’ll get everything you’re looking for in a mild performance increase and better valvetrain.
Yeah, lower compression, but you can always have them shaved to make up for the compression or be happy with the ability to run 87 octane.