I have a set of 74cc heads ready for my engine build. Im about to build up the short block. I was going to build it as a 350, but now looking at building it to 383ci. My question is " with the 74cc heads should I be choosing dished pistons or flat tops?".".How many compression ratio points does the stroking to 383 add to a 350?". Here in New Zealand we have 91 and 95octane unleaded and very few gas stations have 98octane unleaded, so I don't want to run too high compression that I would have to use 98octane gas. Thanks for help with this.
C/R = cylinder volume/head volume; I calculated the 383/74cc heads will give 10.6 c/r, as opposed to the 350/74cc heads giving 9.6 c/r with flat top pistons flush with the block. Someone more knowledgeable might chip in with real world experience though.
My 1990 Corvette 350 I believe has 58cc chambers (Alloy heads). I built it into an internally balanced 383 using forged flat tops to run on regular gas here in Australia.
when doing the build pay close attention to the deck height , normal blocks have up to .15 in the hole ( this is top of piston to deck top where your carbon ridge would have been ) this too will lower your compression . If you go with any surface decking This will need to be checked during mock measurement build . On another note if you degree the cam in when building the engine could make the difference in a lot of hidden power . Good luck . My dad and I built this years ago 630 solid roller 220 dart iron eagles ran mid 11's in the 1/4 mile . 51 chevy truck in family over 15 years my brother in law traded for ex drag car to put back on street . by kuhn1941 posted Feb 21, 2013 at 4:52 AM
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