66valiant, Your build has caught my interest.... Ihave a 318 in my 63 dart and was going to swap for a 360 but, I just can't seem to save the money for it. I also am running the j-heads from a 360 with a performer rpm manifold. the rpm manifold has the larger intake runners to fit the j-heads better. I didn't know much about the compression loss swapping to the bigger heads when I did it and now I have no bottom end. I was wanting to shave my heads also. You said you went 60 thousandths on yours. Did you have to shave the intake? I was also wondering if you are running flattop pistons or the ones with the valve reliefs. Also mopar performance sells a thin head gasket (i believe it's .021 compressed) would this be safe to run with stock pistons and a mild lift cam? I already have adjustable rockers and headers. My heads were rebuilt less than 6 months ago and run great.