Technical Help with mid plate i.d.

I have this mid plate and having trouble figuring what engine that it would fits. It is to bolt a chevy transmission to something. I tried a big block mopar and no go. Thought the engine imprint pattern my be help but I haven't had any luck yet.
Thanks James.

 

Looks like powerglide to 426 Hemi .

 

yup, Chevy to big block Mopar

 

Guess I need to get that 400 dug out and size it up.
Thanks

 

So your first post was you tried a big block Mopar ?