87firebird

I have a 1987 firebird with a 2.8L v6. I was running lean and ended up puttng a hole in a piston. i took that engine out and was looking for a 350 but im still going to college and i dont have the time or money right now to change motor mounts, tranny, rear end, and change over to carburated. so i picked up another 2.8L off ebay just so i can get it back on the road and guy said it ran when he took it out only has 20K miles on it. but i got it home and started moving stuff. Thats when I noticed i can pretty much crank it over by hand. So I guess my question would be is that normal? i know how to do a compression test on a motor that is in the car cuz you just turn the key and let it crank a few times but have no idea how to do it on an engine that is by itself. Any ideas or info would be great thanks!!