318?

better is in the eye of the beholder.

the early blocks around 1970 have been proven capable of a 4'' over bore.
dont know if the later can do that.

If using factory hyd roller lifters is in your plans, the 84-89'ish 318 is what you'd want.

The pre '73 318 all have the lighter & dinkier floating pin rods.
after all that... they are ll just 318's