Mopar 413/426 Max Wedge block casting number confusion

Brooks James said
After tons of research, and talking to experts , the block is not a Maxie. It's a std 426 motor 1964 even though all the block markings are for a 413 ????? No
One has a take on that.

Several possibilities:

Truck block
59-65 Passenger car

What brand motor home did it come out of? It’s possible that they just grabbed a block and tossed on the line when they were short of 426 blocks