[b-man]

I agree with first decking the block square (of course your machinist will be removing the least amount of material to achieve this) and then ordering your pistons with the proper pin height to achieve as close to zero deck as possible.

In my case I was looking for the pistons to be at .005”’above the deck since I was trying to get a .040” quench distance using a .045” crushed thickness Butler head gasket. As you probably already know my pistons ended up.007” to .008”’above the deck giving me a .037” to .038” quench distance.

Generally most engine builders look for .040” for steel rod engines and .050” for engines equipped with aluminum rods. As tight as .035” is perfectly fine and I’m pretty sure some might even get away with a .030” quench distance.

Carbon buildup will be minimized with a nice tight quench and a good tune. I really can’t say what laying back the chamber wall might achieve, on my 421 I pretty much let my friend who built the engine have free reign when he opened up the chambers. I think he was mainly looking to add a few ccs to help lower the compression and perhaps soften up the chambers a bit to help prevent detonation.