WTB : Black Iroc-Z

[The Boss]

Originally Posted by al8apex

The BEST of those years would be a G80 performance axle equipped 1989 with the N-10 dual cat exhaust.

The most fun would be the LB9 305 5 speed G80.

The G80 will include the "1LE" rear brakes and positraction, but then ALL 1989 & up f bodies got the larger rear brakes in 1989.

They did make a few 1990 IROC's, but it was a very short production model as they introduced the 1991 model style very early. The 1990 got the air bag steering wheel, certainly the rarest IROC made.

G80 was just the Posi Rear RPO, G92 was the performance gears RPO code and not all of the 89's got the N10 exhaust as it was phased in that year. The 89 & up cars that got the "1LE" rear brakes (larger, aluminum Borg Warner calipers) were those equipped with the J65 4 Wheel Disk Brakes package. The nice thing about ordering a L98 5.7 model IROC was that you got all of the good stuff with it - the G80 posi, G92 3:23 gears, J65 rear disc, KC4 engine oil cooler and the power steering cooler that was amazingly similar to the ones on the 69 TA's.

Not all IROC's were built the same, and unless you check the RPO codes, an LB9/Auto can easily be disguised as a L98 one - but they are vastly different animals. The LB9 in auto form was neutered with the smaller cam while the LB9 coupled with the 5spd (MK6 World Class T5 in 88 & up) got the same cam as the 350. The only exception here is the 85 models that got the Corvette L98 Cam in the LB9 and was only available in auto form. Those are great cars to own as they are responsive in auto form. Don't buy an 86 at all, it was the low point of the bunch with the awkward high mounted stop light & the smaller cam, no 5spd & no 5.7.

1990 is the shortest production year ever for the Camaro & Firebird starting in the summer of 1989 and ending on December 31, 1989 - there were NO 1990 Camaros or Firebirds built in 1990. 1991 model year started on January 1st, 1990 and ended in the summer of 1991.

[al8apex]

Originally Posted by The Boss

G80 was just the Posi Rear RPO, G92 was the performance gears RPO code and not all of the 89's got the N10 exhaust as it was phased in that year.

my brain fade, G92 is correct, any 89-90 IROC with G92 / N10 is the one to have, all others are "cruisers"

[al8apex]

Originally Posted by The Boss

The nice thing about ordering a L98 5.7 model IROC was that you got all of the good stuff with it - the G80 posi, G92 3:23 gears, J65 rear disc, KC4 engine oil cooler and the power steering cooler that was amazingly similar to the ones on the 69 TA's.

not true, you can have a 5.7 IROC without G92 and you get single exhaust/cats.

Because of the mid year phase in of the N10 exhaust, the early 89 F body cars (C & P) with G92 didn't get the N10.

however all Pontiac Formulas/Trans Ams DID get G92 with the 5.7 after the intro date, not true with the Camaros

FYI, ANY LB9 G92 5-speed will be the "good" one

Co-drove at many, many SCCA events with one of the "father's" of the 1LE, used to know part numbers upside down, time is a cruel thing ... :-)

[The Boss]

Originally Posted by al8apex

not true, you can have a 5.7 IROC without G92 and you get single exhaust/cats.

You are wrong here, ALL of the 5.7 cars got all of the equipment I listed above regardless if they included the G92 or not - it was all part of the B2L package.

Originally Posted by al8apex

not true, you can have a 5.7 IROC without G92 and you get single exhaust/cats.

Because of the mid year phase in of the N10 exhaust, the early 89 F body cars with G92 didn't get the N10.

however all Pontiacs Formulas/Trans Ams DID get G92 with the 5.7, not true with the Camaros

Mid year N10 introduction bulletin for Pontiac.

[Bigbirdxx]

That is good info. I really like the bodystyle and Iroc attitude. I actually attended an Iroc Race back around 1987 at Nazareth Speedway, Pennsylvania. What a time

[70 copo]

The Ohio Plant agrees...

[Bigbirdxx]

This is great info for all. Thanks guys for your input.

[Bigbirdxx]

This is turning out to be a great Thread

[The Boss]

The years were not mutually exclusive however - different years used different combinations of RPO codes. 91 & 92 Z28's with the L98 required G92 to get the 3:23 gears 87-90 did not. Shortages also caused the replacement of the J65 rear discs with the J41 drums in various years. 85-90 got the Australian built Borg Warner 9 bolt (the better rear) 91/92 got the 10 bolt.

It's a tangled web of inconsistencies and changes - when the OP finds a car and wants to check it out - let me know the VIN & I may be able to pull the entire RPO list for you to confirm it.

[Chazman]

Not for sale but figured I'd post:




1989 IROC-Z. Ordered new by me. LB9, 5 speed, G92, (which bundled), N10 dual cats, 3.45 BW Aussie 9 bolt with the PBR brakes and KC4 oil cooler. It's also a DX3 decal delete car. 11K miles. For the record, the 5 speed LB9s got the L98 cam instead of the LG4/L03 "peanut cam".

If you wanted a fast one, you needed to know your way around the order book. There is a HUGE difference in performance between the "peanut cam" LB9, single cat exhaust, 700R4, 2.73 rear axle, disc/drum IROC-Z the dealer would stock and the one I special ordered.

I almost ordered it as a 1LE. By my intention was to use it as a daily driver and I was tired of going to work sweaty with no AC. Who knew I'd only have 11K miles on it 28 years later. LOL!