1965 Barracuda with 84 318

The replacement block that I have is a pre-74 (1971 I think). The cracked block is a 1984. Pistons, rods and crank are all ready to install into the 71n block. HOWEVER: the #3 bearing is different (not completely sure...but thrust face dim?).

Anyway; what do I have to do to make the 84 crank fit in the 71 block?