https://goldcountry.craigslist.org/pts/d/1958-small-block-chevy-283/6746920858.html Guy thinks he has a 283 with powerglide, but it's a 4 speed hydro. $100 for the whole works. Get on it!
I am no expert, but that looks like it may be one of the Pontiac, auto trans combos GMC used in trucks during the mid to late fifties?
GMC trucks ran Ponchos and hydros....Chevy trucks ran small blocks and hydros...probably out of a 1955 and later Chevy truck. They never ran a powerglide in the '55 and newer trucks as far as I know..if you opted for an automatic, you got a hydro.
Just bought a 40,000 mile 283 out of a '61 bubbletop. Guy opted for a 348 update. It was cheap and I got to hear it run.