360 heads on 318

Do the math to determine the compression ratio, then either pick a cam that works with that CR, or mill the heads and/or deck to get the CR up, and then pick a cam. If that's not an option for you, a thinner head gasket will raise the CR negligibly, but probably not enough. Just bolting them on to a stock 318 will probably hurt more than it will help; you will gain flow, but lose velocity, so it will pretty much cancel each other out, and probably cost on the low end..