I did a little digging and found someone else who's made a shim for a 782 with a Honda repower (different beast I know but it adds credence to shimming the gearbox). And yes I know; he kept it mounted flat, but check out the other link I posted below. Scroll down, you'll see pictures.
http://farmallcub.com/phpBB2/viewtop...art=15&t=14796
And here's one more link I found that shows someone had to make custom spacers to make the QA42A fit on a 782 because the engine is angled up at the front about 3°. He did it slightly different but the end result was the same; an angled gearbox
http://mgonitzke.net16.net/QA36A.html