I hope you managed to get the block adapter ring, flywheel, starter, and other accessories along with the Powerglide. Since that setup was not available as original equipment in pickups, you're on your own where fabricating mounts is concerned. Once it's all cobbled together, you'll discover why we used to say "The Powerglide has two speeds- - - -too low and too high!"

There are much better options where automatics behind a 235 are concerned. The cast iron Powerglide is heavy, slippy, and not very appropriate in a truck application. A 700R4/4L60 (same transmission, different name) would be a much better choice, and it includes an overdrive 4th. gear. The effort to adapt it would be similar to what's involved in making the Powerglide work.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!