I just watched "The Slams" lol, pretty entertaining 70's prison movie with the one and only Jim Brown. Pretty brutal movie too, one guy gets his limbs ripped apart in a cement truck (he had it coming though) and another guy had this liquid metal stuff poured all over his face.
https://www.youtube.com/watch?v=SeWvvGdJ6I8
Definitely not as cheesy as the trailer makes it seem, the trailer makes it look like any other blaxpotation film. Some action movies I can find quite boring but this one gets my recommendation.