383 mild street build

[Curiousyellow71]

I know it's nice to buy a piston that drops in...But depending on whether a piston has a solid or hollow dome...it is possible to remove part or all of the dome...get the compression EXACTLY where you want. That is making the assumption that the dome is removable. Some are...some aren't. Occasionally you can pick up some very expensive pistons that no one wants because the compression is to high and just shave the dome off turn them into a flat top. Shaving domes and flycutting valve releifs...both have some cost..but often necessary.

 

[Brett350]

Old TRW no valve relief forged, .030" over. I talked to a fellow that had the same piston to deck clearance as me, same gasket, same valve size. He ran the old 292 509 Purple cam, and had sufficient clearance, but not by a ton. I had intentions of using the MP 528 solid, which should actually have better clearance, but never got around to swapping it in. If your cam has .500" lift or more, I'd really suggest checking clearance with a no valve relief piston.

Yeah that's why I was hesitant to consider flat tops with no reliefs. Thanks again.

 

[66Satellite47]

IMHO, valve reliefs with enough depth & diameter allows future cam choices. Remember piston to valve clearance depends on the cam profile, not advertised lift. CR much above 9.5 seems tough with today's pump gas & iron heads. My aluminum EDE RPM's worked fine at 10.5 actual with 91-93. Again basic pocket porting the 915's gains you a ton of power/torque. A modern "race" valve job bottom cut can do much of that.

 

[Curiousyellow71]

The cam is also important if you want to push the compression. We run 10.5 with iron heads...but the cam we run has lots of seat timing...bleeds compression off. My thought is the voodoo 703 is not a cam that you can run much past 9.5 without pulling timing out.