This is a weird problem ,back in feburary my transmission went out and i had it replace with a remaned.It's a TH350. Ever since i replace it i have had whine coming from the back of my 69 that can only be from inside the vehicle. it sounds like the whine an eletric fuel pumps make before its going to go out. i have had a few poeple look at it. Some say u joints, other's said rear axles. I had both front wheel bearing, both u joints, and the end axle rebuilt, its a 12 bolt with a open diff and 2:56 gear, and the whine is still there. has anyone ever heard of a whine coming from a transmission. its not low on fluid. someone said it might be coming from the rear still because im using 75-90 royal purple in it and it was the orignnal ring and pinion but its the same sound. you can only hear when its under load. the only change i can tell is at first it would start at speeds over 45 and now after i changed everything its starts at 35 or faster. if anyone knows anyone in the Peoria, Illinois that could help, i would really appreciate it.