[Mart]

I just looked at my 33 which had a 59A swapped in in the 50s. It looks like the loop has been trimmed off the U bolt abutment and the pulley was trimmed down. It needs to be just a little longer than the crank so a thick washer can pull it tight. I think I would prefer this approach rather than modifying the crank especially with an already built up engine.

The motor needs spacers to raise it up off the mounts. I made my own.

People have been doing this swap since the 1950s. Belt changes can be a challenge. having the motor spaced just high enough to snake the belt through helps.