Compression Question.

I have built a 468 striker with and Eagle crank.. I can get the Part number if needed. It has BB Chevy h-beam rods.. also can get the part number if needed. And short stroker pistons..again if you need the part number I can provide it..now here’s my question. I took a stock 1970 Pontiac block with #15 heads that are ported and polished with big valves installed.  All the above parts went to my machine shop.. a VERY high end BTW.. so VERY trustworthy. They said if I wanted to be 10.5:1 I had to deck the block, mill the heads and re-cut my intake to match... now... here is my question and I hope someone is smarter than me... I have a chance to buy an M1 procharger CHEAP. If I were to buy the 87cc edelbrocks and bolt them on stock or even a set of smogger  6x Stock would that lower my ratio enough??? I hope I’m not confusing, thanks for any help. #ponchopower