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I am rebuilding a 396 for my c3. It’s my first time really tearing this far into a motor. I don’t know a lot about these big blocks.
it appears I have closed chamber heads and Dome pistons. I want to figure out what the max lift cam I can put into this motor with these heads and pistons.
what do you need tons of valve lift for? high lift is for high flow at high rpm's. requires heavy springs. shortens valvetrain life. are you taking this guy to the track to see what times you can pull? if so, start with a 454 or 496. if this is a driver with a big block in it, a ZZ502 cam or similar will provide plenty of power, sound like a race car and still be driveable and dependable. head id. a 215 is a fairly small semi-closed chambered head. decent for upping the compression ratio of flat piston truck 454's. what do you have for pistons?
Thanks for the reply. I have no problem intention of putting a huge cam in it. I just wanted to know my limits.
It has the 215 closed chamber heads and what appear to be dome pistons.
I am looking at this cam for this 396. I am up for suggestions. This corvette will just be a play toy. No plans of going to the track.
chevy stopped putting big blocks in vettes in 74. if you have a sawzall and a welder you can get a 502 in a chevette. doesn't mean it is a good idea. but they still made SS396's in 1970, even though they were 402's. so a 396 in a 68 vette is not blasphemy.
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
I got one.....Like it alot, but the Issue is finding aluminum heads that will fit in the narrow/ stock cylinder bore. Most have the larger valves that fit the 4.25 bore of the 427 and 454. And finding a modern intake that will fit easily under the hood can be a challenge.
You can put a nice cam in it and get some good rpms out of it but the heads are the limiting factor. If you want some big rpms just get everything rebalanced and you should be able to get to 7K. Also there are 2 blocks that are listed as 396/ 427 and the only 2 that I have read that would be available to reliably punch out to the 427 if you think you want to go that way.. But If you want to spend the money on those iron heads, get a good port job on them and the biggest valves you can squeeze in to that cylinder to get the flow numbers up. You will be very happy with a good cam with decent flowing heads. Look at the duration numbers versus the lift numbers. More duration will give you better results versus large lift numbers alone. Just changing head characteristics on a desk top dyno really bumps up the power on those motors. I love big blocks but just running a tame one really eats the gas compared to a small block, just be prepared if you like to drive past gas stations instead of stopping...LOL
1968 396 piston and head ID
