My Girlfreind just scored a 73 Chevy pickup(Crate 350, SM465, NP205, 4" Lift, 35's). When in 4H or 4L, the rear end chirps alot, like the gears in the axles are different. I dont think its a locker, because it does it at idle, in a straight line. After, its a pain to get it out of gear. The front has a tag that says 41.11-3.73, what ratio is this that?