318 Difference?

I have a 1970 and a 1977 318, I am going to rebuild one of them and put in my 76 W100. Witch one should I rebuild? The 70 is a higher compression motor than the 77? Right? The 70 crank is not in good shape, the 77 is in good shape, will the 77 crank work in the 70 motor? The 77 has factory pistons, the 70 has different pistons, cylinders look good in both blocks. Was just going to hone the cylinders and go. Any thoughts? Thanks.