Diff. Between on th350/powerglide?

I know (or think I do) that there's a difference between a th350/400 and a powerglide as far as the the mounting holes. I have a mount for a 350, and I think for the powerglide it's 1/2" back from a 350 for the mount. Anyone know?

 

When I went from a glide to a 350 it just bolted in. A 750 is different.

 

post #2 in this thread has a good comparison graphic that I saved:

http://www.jalopyjournal.com/forum/showthread.php?p=2616777#post2616777