Went through 3 ships before I found d one that would work on my block, they all kept telling g me they would not work on amc blocks because of the high nickel and to hard, just tears up there bits.
For mud drags had to stay with the 304, looked all over at the time, 17 years ago trying to find a 401 block with no luck, and a pita finding a cast 4 brl intake for a 76 v8, different mounting bolts locations than prior.

They still have the amc nashionals in nashville?
With the huge amc swap meet?
Might be a great place to unload.