76 Cad 500 into '75 Chevy 3/4 ton 4x4

I recently picked up a running '76 Cad 500 out of an Eldorado which has a stuck valve for $350. I plan on putting it in my 1975 Silverado 4x4 and was wondering if anyone has experience with a swap like this. What kind of modifications am I going run into, what kind of tranny should I use, because I'm not sure I trust my TH-350 with all that power. Also, anyone know where I could find a set of 76cc heads and 10:1 pistons for this 500, because if memory serves, '76 had 120cc heads with 8.5:1 compression. Thanks in advance for all your help.

You may be aware that there are 2 differnet GM V8 bell housing bolt patterns; one for Chevy small and big blocks, and one for all other V8's, including Buick - Olds - Pontiac - Cadillac. (BOP pattern)

By far the most difficult problem you will have is finding a 4x4 auto transmission with a BOP bolt pattern. Your existing trans will not fit the Caddy engine, and obviously no 4x4 trucks came with
Buick - Olds - Pontiac - Cadillac engines.

There is only one possibility I know of..... the late '60's and early '70 Jeep 4x4 Commando's came with Buick 225 cid V6 engines.....and some came with a Buick 350 V8. The trans and transfer case from one would fit the Caddy V8 and may be adapted to the Chevy truck .

If your truck was a 2 wheel drive, the swap would be easy; you would just need to find an ordinary THM 400 trans with a BOP bolt pattern and lengthen/modify your driveshaft to fit.