I just installed a 4.10 posi in my 91 RS. It is bolted to a 305TBI with a T5. There is a high whining sound from the rear when I cruise around 50mph. IS this normal? Im soon gonna bolt a 350 with a richmond 5spd(if i can find one at a good price).

 

I have a 91Formula 305 tbi with a 700R4 xmission. I first installed Richmond 3.73's in place of the 2.73's, and the 3.73's made a lot of noise (I have heard that is common with 3.73's). I have since installed Richmond 4.10's with a Auburn posi. They are very quite. I had the Pontiac service department install them because the tolerances are so critical and the guages are expensive. I hope this helps.

Good luck,
Don

 

sounds like they werent setup correctly if they are whining, although some do claim that richmonds are noisier than other gears, u didnt mention what kind you have.