[GallopinGhost]

Having trouble finding enough P/V clearance. Hope someone here can give some advice. It’s a 70 dodge 383 for stock. Iron heads. Pistons are flat top without valve reliefs. Short block is finished, cam installed. I'm using a spare cylinder head to make measurements so I can give directions to the cylinder head builder so he can finish the heads.


I’m shooting for at a minimum .025/.060 when done. Right now I have .040/.057. To get that number, I’m comparing valve drop numbers from my heads to the new one at the cylinder guys shop. I'm setting valves at hot lash setting of .008” , solid lifters. The new heads haven’t been decked yet, although the valve job is done. Heads are at 88 cc now, min. spec is 79.5. It should take 0.040 to get the chambers to min. spec. I’ve moved the cam around to find the sweet spot for the intake clearance, it’s at 4 degrees retarded now. I‘m thinking of decking the heads 0.020 and sinking the valves 0.010/0.025. It seems to be a juggling act between sinking valves, how much to cut the cylinder deck, and or change gaskets. I’d like to keep the current spec gasket, which is a steel shim .021”


I hope I've explained that clearly enough, this is my first time building a stocker engine. I guess the question is what kills power more, sinking valves or losing compression ?