@famous bob its hard to stick a number on what it takes to roll over an assembled engine without measuring it. But I can tell you that if you had the rod caps mixed up or something as serious as that, the engine would not last very long when running. A friend of mine in high school built a small block Chevy and all the caps were mixed up. He couldn’t turn it with a wrench. Decided to put it together and crank it on the starter. It started and ran, but not well and only lived about 15 minutes. For a comparison to your 505 the 468 BBC in my boat assembled without plugs in it takes at least a two foot pipe on the wrench to roll it over. It’s got lots of valve spring pressure and big bores so lots of surface area on the rings.