273 302 318 340 build

First that cam is nasty for a 340 or a 360 with 3.23 gears. I think I'd run the 318 with the heads it has and slap that 340 intake and Edelbrock carb on top. Get a 340 cam, lifters and valve springs or an updated cam close to it. Use the 340 exhaust manifolds. Replace the seals, gaskets, except the head gaskets, and brass freeze plugs. Maybe a windage tray. About as cheap and easy as it gets. Once I take one apart I can't stop till it is completely done. You will also need an adapter to mate the torque converter to the larger pilot on the 318 crank. Then, if you want you can take your time with the 302 heads.