Starter to block interference.

Did a little work to the Barracuda yesterday, while installing the starter I was having an issue with it not seating straight and flat against the transmission, it was at an angle having more space between the terminal end of the starter motor in the block. It appeared to be hitting the block right where that hole is in the block with a slight machine angle right below the motor transmission Bolt. Tried two different mini starter's , no difference, going to try a regular size starter. You can see where the mini starter was hitting the block on the starter and a block.
Is it due to the fact that it is a 360 block and a 904 transmission? Has anybody else had this experience?