irocs
 

did all irocs have posi rears?

Mayyyyyyybe

My 88 Iroc-Z 305 TBI does NOT have a posi.
J0n can tell you that

dont think so...

my 87 has a 2.73 posi though...

no they don't.....only some have posi.

ok just woundering because i might buy a 86 iroc-z for 500 in delran.

what color is it? My friend curt had one and sold it. I dont know where it ended up, but it wasn't in too great of shape. It was mulitple shades of blue with gold IROC rims.

I didn't think you could get an IROC with TBI?? Â*I thought all had Tuned Port atleast from 87 on....someone clear this up for me.

Pretty sure they were all TPI, probably a typo. But anyway for the posi look atthe rear diff and see if there is ametal tag on one of the bolts in the cover, if there is it is Posi (of course many get lost/removed). Otherwise if the RPO codes are there look it up, I think Posi is a G81 or G86 RPO code if memory serves. and then it will be with one of the other following RPO codes also for gear ratio
GU2 2.73
GU5 3.23
GU6 3.42 <----- not sure if it was available on an IROC

You could get IROCs with TBI and LG4 engines, common misconception that they were all TPI. GTAs were TPI only.

The Posi code was G80

GU1 Â*AXLE,RR 2.41 RATIO Â*
GU2 Â*AXLE,RR 2.73 RATIO Â*
GU4 Â*AXLE,RR 3.08 RATIO Â*
GU5 Â*AXLE,RR 3.23 RATIO Â*
GU6 Â*AXLE,RR 3.42 RATIO Â*
GT4 Â*AXLE,RR 3.73 RATIO Â*
GT5 Â*AXLE,RR 4.10 RATIO Â*

- Justin

its red with black interior.

I think that just 87 IROC's came with either the 305 or the 350 TPI. After the 1987 model year, the Z28 went away till 1991 when Chevy lost IROC series.

any year 3rd gen with Z28 or Iroc badging wold have a V8 in it. from 82-86 the base V8 was the LG4. 82-84(? from memory) the CFI 305 and L69 were available as options.
1985 started the offering of the LB9(305 tpi) and in 1988 the LO3(305 tbi) was added as an option. 1987 was teh last year that a carbed engine, the LG4, was offered in an f-body. a few months into the 1987 model year the L98 came online(it was available for order from day one).
1988 marked teh first year that the "base" engine in an IROC Z28 optioned vehicle was teh LB9. it coudl be deleted down for a minor price break to the LO3. this is a very very common option.
as for the GTA's only having been made with tpi. i don't know what to say. i have seen so many strangely optioned cars before that i don't count anything out any more. V6's equiped and coded for the JG1 aluminum drive shaft, Iron Duke 4cyl powered cars with 2.73 gears, i even saw a 1LE at a car show once that had 3.08 gears in it.
gm was not real picky about what they woudl or would not accept for orders. they just wanted to move units. worst part is that their record keeping was very very bad. so it is hard to reserach these things as well.

later
tim

:nod: