Trying to plan out my summer projects. I want to swap in this new 3rd member to replace my open (I think)3.23s and gain sure grip. 489 case with 3.91s This was pulled from my fathers car several years back and has just been sitting since. I did nothing but clean it up and paint over the surface rust. Is there anything I should check or do before the swap? Best I can gather from him it was working fine before he removed it he just wanted a more highway friendly gear. He says it might have had a slight growl but it's been a bit and he's not positive. Ideally I can just slap it in there for now as I may be changing gears soon anyway. Afraid the 3.91s may be a bit too low for my liking but hoping my 28in tire will offset that some. Sorry for the long post. Any tips or advice appreciated.