I'm trying to figure out if the 86 iroc I picked up has the factory rear axle.RPO code has GU5 thats a 3.23 .The stamp on the axle has 9JA C032 1 on it and thats not in the Haynes repair chart for factory codes.This car has been messed with.Think a 350turbo may be in it.The tailshaft looks like a 700r4 but the crossmember that holds it up sits rear a little and the tork arm only reaches the rear most hole in the tailshaft and the dumbies drilled a hole in the tork arm and bolted it to it with a mess of a job.