During my 355 build up have had block decked & pistons machined to give each piston the desired .035" quench, (.015" shim gasket & piston .020" below deck) however upon build I found conrod big ends to be .0015" oversize so replaced with eagle "I" beams unfortunately the quench now appears to be .031" on most & .030" on remaining.
Question is this too small ? The motor will be spun to 6000 rpm max, the pistons (flat top hypereutectic .030" over) are running .0015" clearance so should'nt rock much thereby reducing clearance further, als 30 grams lither than standard G.M.
Dennis has a good point. .035" is about the minimum quench clearance. This assumes a loose fitting forged slug but there is probably plenty of quench effect between .035" and up to around .043" or so. After that I beleve the effect starts to drop off rapidly. This is from memory so maybe the figure is higher.
You could be fine with that tight fitting Hypereutectic piston but no need to risk it.