I am in the market for a new short block and I was leading toward the zz383 but I dont think I will make enough compression with it for what I want to do with it. I have AFR 195 74cc heads. I am looking for 10.0:1 compression. I dont think I will acheive that with the zz383. SDPC claims 9.1:1 with 64cc heads and 8.4:1 w/ 72cc heads. this seems a little low, no? I will have the heads milled but the less I have to remove the better i think.

Now for my question, will I be better off going with the zz4 and still having my heads milled for a higher compression engine and try to find hp somewhere else?

 

If you go with a 383 shortblock, which I'm assuming uses -4cc F/T pistons, .015 (FelPro 1094) gasket, std deck height you'll be right at 10:1 compression.

With a 350 and the same stuff you'll be at 9.3:1. You would have to shave the heads to 67cc chambers for 10:1 compression on the 350.

I wouldn't reccomend shaving the heads, it should be done as a last resort (IMO). You might be better off with a different motor (if you go with a 350) that has domed pistons then use a .041 composite gasket to acheive 10:1. GMPP makes good motors, but there's other places that make them just as well, if not better. Just something to think about...