So then did Pat get it wrong? Cause that would end up putting his SCR at 10.2:1. Again i would like to re-iterate that i am a novice engine builder still working on my first build. And to go along with the 351 piston topic, check out these ones i found (im sure they have been mentioned before but i just came across them). Looks like they would come up with a 9.7:1 SCR, that is with the promaxx head i have.The CH of an non-planed block at 0 deck height would be 1.80": 10" deck - 1/2 stroke (1.99) - rod length (6.21) = 10 - 6.21 - 1.99 = 1.8. I've not come across any piston offering with this number. They all leave the piston under deck in varying amounts. Tallest CH I have seen is 1.778" , .022" under deck. A 1.776 CH is .024" deep, not .032"