273 302 318 340 build

You really changed directions.... good for you! Yes, use the larger heads for the compression ratio to be in the mid 9's; I get 9.6 or so with .028" thick head gaskets and the rest stock. (Deck height, rods, etc.)

DCR is coming out to a bit over 8:1 with the 270 solid cam installed at 106 degrees ICL, and .028" head gaskets, so you are as far up as you can easily go with that. Hope you have a good budget for tires! LOL