I was under the impression that a 427 required the cam location change. I know there can be problems with that stroke arrangment.
1BAD80, were you able to find an oem block that worked. Also, anyone know the cam lift limitations. I would guess a big roller would be out of the question if trying to use an oem block.
I am curious because I have toyed with the idea of a 427, but my budget is not deep enough for a new block yet. Maybe the next buildup...