Originally Posted by sp1x

Hi.
I want to get 3.5L with my BOA Cosworth engine.
I plan to use 3.7/4.7 Chrysler flat top pistons. But standart pistons have dish with valve reliefs.
So should I I deck my block to have the pistons flush with top of block? I'm afraid that valves will hit pistons in this case.
What compression will I get without decking the block? Standart compression is 9.7