finally it looks like V-8 time

Ok, I have decided to go with a stock 273 4bbl intake and small AFB carter.
On to the next issue, low compression. In another post someone mentioned putting 318 Poly pistons in an LA 318 gives you around 9.5:1 compression. has anyone done this? I do happen to have a nice set of standard Poly Pistons here. (this is turning out to be a real junk yard build!)
next up the final decision on heads, I have the stock 78 heads which have the advantage of having hardened seats but I also have several options here as well.