MrWylde

i have a 96' GM crate 454 stock. this engine pulled a valve seat at around 8,000 miles and all i have done to it is had the valve seat replaced and the block and heads dipped/checked and installed new valves and springs to go with my cam. What i want to know is can i run a set of stock ls6 .095 domed pistons in this engine and will this improve the perfomance of my build as oposed to flat tops, here is the cam i am using


Comp Cams CL11-207-3


Thanks in advance

9000th01ss

iTrader: (10)

Whats the specs on the heads?
Need to know combustion chamber cc, and intake port size (or at least the shape--small oval, large oval, etc)
Need to know this to figure dynamic compression with the cam you posted.

MrWylde

the casting on the heads is 10114156, they are oval port and according to all i can find 118cc, however, every page i have found on these heads say they are an open chamber head and they are not. these are a closed chamber with only enough for the valve recess. as far as small or large ovals, i really don't know how to tell the difference.

9000th01ss

iTrader: (10)

No way. Those are 156 castings, those are the same heads that came stock on my silverado 3500. They are peanut port heads, meaning the intake ports are tiny. They are so small they cannot support a mild cam with stock compression. In fact you can take the 156's off and put on some large oval port heads, with no other mods and gain a noticable amount of power.

So do not put dome top pistons under those heads, you might be one of very few who have tried only to realize it doesn't work.
Your best bet is to increase compression by using heads with a smaller chamber and bigger ports and leaving the bottom end alone.