1991 RS 305

I'm looking at a rear end out of an 85 Iroc. It has rear disc brakes. In my searches, being the car had an auto I can conclude that it has 3.23's or 3.42's. My question is did the disc brakes only come with the 3.42's (G92 option) and the drums with the 3.23's, or is it possible to have a 3.23 with disc brakes.

Thanks, Matt

JamesC

iTrader: (5)

Yes, that's what my car is equipped with.

Should you be unfamiliar, here's how to determine what ratio the rear is (jerk the diff cover and look): numbers are stamped on the ring and pinion:

41 : 15 = 2.73
40 : 13 = 3.08
42 : 13 = 3.23
41 : 12 = 3.42
41 : 11 = 3.73

JamesC

1991 RS 305

Thanks for the info, JamesC. The guy e-mailed back and sayd it was a 3.42. He also said it wasn't a posi now. Is this even possible, rear out of an 85 Iroc, 3.42, with disc brakes, but not a posi? I would think that the disc brake option alone would make it a posi. The rear has sat fo 20 years, they removed the drivetrain from the car back in 87. is it possible that the wheels are spinning opposite due to it sitting for so long and some parts being dry?

JamesC

iTrader: (5)

IIRC, the posi was an option. If that's the case, then, yes, the rear could be a disc brake rear and not be posi equipped. One way or another, you might request that the seller remove the diff cover and check.

JamesC