Just picked up a 91 Z that was an original 350 car. It has dual cats, ect. It also lists G92 on the option Sheet, along with the 350 motor, but interestingly enough, has a drum brake rear. All the other G92 cars that I have owned were 4 wheel disc cars. It does not list the J65 code, but I thought G92 required J65??? The only thing I can think of is that all 350 cars got G92?????

Can anyone please clear this up for me???

Exactly how many 91 Z's got G92??

Thanks

Tom

 

Tom, i thought the same thing but we also just picked up a 1991 Z/28 with 350 and G92 with rear drum brakes. I have never seen a 350 car with out G92. Some one will know.

 

I have seen some of these to. Kinda weird.

G80: limited slip rearend

G92: performance axle: 3.23 auto, 3.42 stick

I also thought that G92 only came on J65 cars but apprently not.

I do not have the white book but it would break down numbers between G92 and J65, if both numbers same then something wrong. If both numbers different then in fact you could get G92 without J65. Sorry i couldn't be more help.

 

My 91 GTA has L98 without G92..
But it has J65 and rear drums :lala: :lala:

 

I am sure there are more cars with the G92 option than just the 350 cars. I know there are a good number of 305 5-speed G92 cars out there. I thought it was really weird, but I guess it seems to be more of the norm for at least 91's anyway.

Tom

 

Sauron91, how can you have J65 and rear drums? J65 is the four wheel disc option.

 

what exactly does the G92 option include??? I have a 305tpi 5 speed in my 91 TA, with dual cats, and the 3.42 posi rear with drum brakes.........do I have a G92????

 

G92 is your 3.42 rear rear ratio

 

I have a Black 91 Z28 too with the 5.7 Tuned Port Injection L98 and G92 package....and I have drum brakes on the back.....I thought it was kind of weird too.....

 

Yeah it says in the white book that G92 included 4 wheel disks so that is really weird.

 

My understanding from previous posts on this topic is that GM actually ran out of rear disc brakes in 91. And installed drum brakes in their place. Try searching the boards, this topic has come up before.

Mine is an 87 with a tpi 305, automatic, w/g92, it has rear disc brakes on it.

 

my brother has a 91 z29 350 with the g92 and it has rear drums and posi.

 

I got a 91 Z28 with rear drums as well. Labrat is right from what I've heard.

David

 

Yup, there was a point when they were having problems with the rear disk systems so they used the drums for a short time.....

 

my production number is towards the tail end and i have discs........i've seen so many different things come about. as far as i know the only thing to be fact with the l98 option was it came standard with the auto and hardtop........other than that i've seen many options added or deleted over the years.

 

I think 92GTA is correct.

GM was having lots of problems supplying J65 rear disc brakes on G92 optioned F-bodies for the '91MY.

Maybe GM was having "supply" problems with the manufacturer (PBR?) for the rear brake calipers and decided to go back to rear-drums until the problem was solved.

I believe the rear-drums specifically used on these G92/J65 optioned cars were made of aluminum instead of the cast iron used on regular non G92 optioned F-bodies. Right? Or did the use of aluminum drums only apply to the G92/J65 rear-drum brake equipped '91 GTA's only?

Didn't GM do a similar but slightly different thing back in '82-'83 on the Pontiac Firebirds. Since they was running low on rear disc brakes for WS6 optioned T/A's, they decided to create a new (WS7) option that included all of the WS6 stuff except for rear discs.

I remember looking at a G92 optioned B2L/L98 '91 Z28 with rear drums on it a few years ago. I thought it was really a 305/LB9 being "disguised" as a 350/L98 because it had the rear drum brakes in the back.

GM does some strange things sometimes don't they?

 

My car was a special order and it does not have J65 on the option sheet.

I will check tonight to see if it has aluminum drums or not.

I thought it was odd, as this car litterally has every option except rear disc.

Tom

 

Perhaps the GTAs were the only ones with Aluminum drums because mine are cast iron. Unless I got some funky rusting aluminum :-D
David

 

My option code comes up for rear drum brakes with cast iron drums on the 91 350 Z/28.
extreme

 

Nice car extreme!! Could be my twin!


David

 

Yep, mine has Cast Iron drums too....

There is just nothing as sweet as a Black 91 Z!!!!

Tom

 

Nice Black 91 Z28's guys! Mine is exactly the same...but I have the SS ASCD hood