Thanks all. I thought going from a B block to an LA would make things simpler but no dice.
That's why I bought a reproduction bracket. Figured it would be the same. Apparently not.
Will give it a shot but I'm skeptical and concerned I'll end up screwing up the threads in the head.
I did flip it over and that put the bracket way too low.
If that's the case I should go ahead and put the balancer/pulley on it and work out from that.