The early 50 oz cranks just weren't very good castings. Both I saw had broken completely in two at the #2, 3 or 4 journals(this was back in the mid 80's so the actual breaking point of either, I just don't recall). Not at the front snout. And one was in an early 80's Lincoln Town car, the other in a similar year F150. Neither was subjected to any unusual abuse and neither had nowwhere near 100K miles on them. Just a warning, don't be surprised if that one breaks. The blocks are fine as far as that goes, just not worth the money some want for them. I wouldn't pay more than scrap value for a 1970 to an 84 302. The blocks and internals are nothing to write home about and good roller short blocks can be had for the same money.