A833 buying tips?

Good morning, FABO!

I'm looking to swap in a 4 speed for my 727 in the 74 Barracuda 440. I found a (mostly) complete setup that includes transmission, big block bell housing, shifter with rods, flywheel, scatter shield, hardware, and few odds & ends. No clutch, pedals, or z-bar that I can see. I've contacted Brewer's Performance, and they've advised of the changes I'd need to make it work on my car (mainly a different tail shaft housing), so I should be good to go in that regard.

Here are my questions: what should I look at specifically when inspecting the transmission? I have heard of folks removing the side cover, but what am I looking at/for? How should it feel when I spin the input shaft? What are some red flags that would make you not want to buy the transmission? The seller says he pulled it out of a 63 Savoy and posted pictures of the car, which is very nice. I'm going to ask why he pulled it out, next time we talk. He seems very open and is providing any pictures I ask for.

Thanks in advance for your help.