Originally Posted by F-BIRD'88
You are going on faith based on unsound advise and inaccurate data.
If you are using a 64cc head build it with a dished piston.
If you want a flat top 383 piston use a 70cc head on it.
You do not want to run it right on the edge. Don;t get all nuts on the cr.
An it don't matter what cam you stuff in it.
The trouble is you are only shopping price on the 383 kits.
The flat top piston kit is cheaper for a reason.
Its a bad choice for a 383 with 64cc heads on pump gas.
if you want a 64cc head get the kit with the -12cc dished pistons
tech math and advice is always wrong.
There is no benefit to trying to ride the edge of the compression limit.
Do not get all nuts on compression or try to max it out.
10.5:1 is MORE THAN ENOUGH.
Not to start an interweb pssing contest but that article essentially backs up tech, math is math, and assuming the numbers given are accurate, it shows 10.7 static....the article repeatedly states ABOUT 10.5 as the practical limit, and on 93 as opposed to the readily avail 94 around here. And agreed that it comes down to dcr which at 8.82 isn't extremely aggressive with a good tune and 94. It doesnt seem to take into consideration alum vs iron heads either which seems significant. I would agree at 11+ comp that its diminishing returns.....high risk, little to gain, but at ABOUT 10.7 it doesn't sound like a ragged edge deal.....keep the timing right, run good readily avail fuel, keep it cool, and don't be retarted with it in 35° weather.....or 90°+ I should say for you American lads......