I know there were 1000-1200 Formulas made in 92, and about 200 or so of them were t top with the 350. I'm proud as heck of mine, love it. Needs a little work here and there, but I'm glad to have it. Bought it about 8 mo's ago for about $4,800, and had no idea of the rarity of it til weeks later--I'm at 155k now. I've only seen one other t top/350 from 92 on here. It was a Jamaica yellow, I forget the poster who owned it. I've never seen another one in real life--never. Info on t top/350 IROC's welcomed too--original factory combo only of course!

Clean engine bay, someone took care of this car. You can look at the passenger side strut tower and see how far the camber was out, got that fixed since!

Other than some dings here and there and coolant stain from heater core failure, interior is very good.

i have an 88 Iroc 5.7 T top car - Blk gold trim under re-condtruction

What's your production date? I notice you have the black valve covers and the blank throttle body plate but not the textured runners...so I'm guessing May/June? Seems like the July/Aug cars have the textured runners.

BTW, congrats on the purchase! Great car for the price for sure!

There was guy on here years ago with a black one that I can remember.

Alex

That could be. The door sticker is gone, so I don't know the exact date. The build number is 073592, so maybe July, but I don't know--you could be right. The last numbers of my vin are up over 220,000-- so I'm guessing it was later on in the run. I guess if I dug deep enough I could use the vin to find out an exact date. It was built at the Van Nuys plant and shipped to Brown Pontiac in Arlington, VA. I found the factory build sheet inside the door, and the original window sticker in the rear glove box with matching vins on each. IDK if there is a shipment date on the window sticker, there may be.

There is a date on the original window sticker yes. Wonder why your door stickers are gone? On my 92 GTA when I removed the dash, on the metal frame underneath was an inspection sticker with a hand written date. That should get you within 3 day or so I'd think, it was for my car.

Anyway, not too important, I was just wondering. I've always been fascinated by the parts discrepancies on the mid-late 1992 models as they ran out of parts. It's a good way to judge originality.

I'm guessing the car was repainted at some point and the sticker got removed or sanded off. I really don't know. I guess it's the original door, but there's a chance it might not be. No way to tell. I have date stamps of 92 on both fenders and the under the hood, so I assume they are original. I'll take a closer look at the door. Exciting day tomorrow, I have to take it off and try to move it forward 1/8" because the PO worked on the hinges and incorrectly placed them.

Send me the VIN via PM and I'll look up the car on Compnine.com to see if it shows a build date.

Nice formula. Obviously the original wheels were swapped for T/A wheels. Still clean.

The lightweight PW7 rims on the Formula was required in order to get the 350 and T-Top combo from the factory.

Yeah, I was gonna post this too til I saw yours. You're exactly right, the rims are original. Do you know what GM's reason was for this?

According to compnine.com, based on your VIN, your Formula was built on 1992-06-17

Hey, that's great! Thanks for checking into that for me!

Some people have speculated weight but that seems fishy to me. The acrylic tops add hardly any weight and the cross-lace wheels can't be THAT much lighter than the 16" Formula wheels. I've always thought it looked good though IMHO so whatever lol.

Nice, a June car just like I thought. I'd love to have a that late of a build date.

It could be a specialty/originality thing they did to set them apart for collectibility and etc. just so they would be slightly different than the other Formulas. I've never totally bought the weight thing either. Besides, the Lexan tops probably weigh less than the stock steel top, so why would they be concerned with rim weight? I know the t bar is steel, but still.....Anyway, I had a red 91 with the 5.7 when I was in my 20's. It was a hardtop and had the regular Formula wheels. When I first bought this one I was going to switch the wheels out because I made the same faulty assumption about them being put on later. But the more I look at them the more I like them better than the turbines or whatever they heck theyre called. LOL

Perhaps but I'd say the fact there are tons of 92 Formys with cross-lace wheels in general and not just if they were the 350/t-top optioned one kinda discounts that theory too I'd say. Once Pontiac started offering (in 1991 I think?) the gold cross-lace on the non GTA Trans Am and the black cross-lace on the Formula, lots of people optioned them that way.

Yeah, those are good points too, you may be right. Who the heck knows with GM.

The crosslace are the lightest 16x8 wheel GM made for these cars by a surprisingly large number.
I'm one that believes GM did the wheels and ttops for weight and c.a.f.é. mileage numbers. Or to get rid of extra stock.

There are around 4 92 formula 350s in my small town and one or 2 92 305 5speed R6P formulas. The 350s have black valve covers and only one of the 305s don't. Most were built in the last few months.

Yeah, the mileage numbers and getting rid of stock--THERES a reason that I could believe. That's the best I've heard so far, and gives an actual reason that makes more sense.

I'm going to need to see some published quantifiable numbers to believe the weight thing. For example, just what were the c.a.f.e. numbers at that time and precisely how did they correlate to the Formula; IE are we to believe that the Formula was so heavy (after all a car with no bulky gfx) that it was so borderline they needed to save literally what amounts to a few lbs? I just don't buy it. My understanding is that c.a.f.e. standards apply to the average fleet fuel economy as an entire product line currently offered for sale at a given point in time. So GM needed to save just a few lbs on a Formula because if they had not, it would have adversely affected their entire fleet average mileage statistics for that model year? I call bollox.

Nothing against those who believe it, however where is the proof in the koolaid before I drink it. I've been reading this for years on here and never, ever, seen proof.

I'm willing to bet my 305/t-top GTA weighs a fair bit over what a 350/non t-top Formula of the same year did. So why require an ever so slightly lighter wheel to offset adding the what, 1lb maybe, of t-tops to get a 350/t-top combo? It just doesn't make sense. Or perhaps they thought the lighter wheels offset the weight of that extra 45ci of displacement and the t-tops lol. I'm just saying...it's wasn't 1989 and heavy glass t-tops...

Far as moving inventory, ehhh, doubtful. Those wheels were optional, if you are going to clear inventory, make them standard or offer a discount for deleting the standard Formy wheels and going with the cross-lace, neither was the case.

I think I'm too stressed at work, playing devils advocate is just entertaining right now haha

Now here is something I could believe, perhaps the weight of added the T-Tops if left un-equalized by the addition of the lighter wheels would have required GM to re-certify The Formula's average rated MPG as stated to the EPA and listed on the window sticker? It would seem odd to see 2 Formula's on a lot side by side, one with a lower rated MPG by 1 lol. But in reality, GM guesses these numbers (ok by mathematical formula), submits them to the EPA, and poof, it's on a window sticker. There was no "certification process" at the time which would have costs GM more money, neither is there now. Even today the EPA is JUST now going to start testing to verify an automakers MPG claim. Plus there were different ratings for the 305 vs the 350 and even manual vs auto, so this would have been nothing new. So yeah, in my eyes the weight/c.a.f.e. thing is a negative until I see some proof.

Now, how much weight did all of the full seam sealer added to the 1992 production process add to the cars?

I read somewhere that the TA was over 300 pounds heavier than the Formula. The ground effects aren't THAT heavy, where is all that weight? BTW, devil's advocate....LOL. That's usually what I do. I guess I'm the good cop on this thread.

I've said many times that I wish someone who worked at GM as a designer or engineer during the thirdgen era would join this forum. Oh the questions that could be answered.....

I think that's on the extreme, for example a fully optioned TA with leather, the 350 so it gets the god awful heavy 4L60, power antenna, the gfx, whole 9 yards vs. a stripped down say 5-spd 1LE Formy or something. I think that's a "wow" statistic someone found and threw out there.

Why can't a TA use the 700r4? Something just occurred to me though. The IROC could also be bought with ttop/5.7. Were the stock IROC wheels that much different where there was no need for a special version for the ttop? Never heard of it, so why with the Firebird? And if the stock Formula wheels were made from the dense material of a neutron star, why were they offered to begin with?....other than they do look kinda cool.......

...and so could the GTA in 1989 and a few in 1990.

A 4L60 is basically a 700R4, just in it's newer redesign configuration which occurred in like 1988. Don't quote me though, I can't recall the exact year they did the redesign and changed the name from 700R4 to 4L60...

The 16" Formy wheels and the 16" GTA wheels both came out in 1987. They needed to look different to better differentiate the models from each other. The weight I think was just inherit to their appearance. Both are Alcoa aluminum wheels I believe.

Oh I see. Auto manufacture nomenclature is not a strength of mine. I've always enjoyed using the XBI-231/22F384, but they added a set screw to the top left housing bracket in 1991, and called it the SDL-381-192a. There's a huge difference when it spins off the top of the vertical arm though. It fixed the balancing issue the XBI had, you'll love it......

Yup so you will love this!

TEARS! Rockwell.... Isn't he the guy that got together with Michael Jackson to sing about how someone was always watching him? I guess his dingle arm issue kept him at a one hit wonder and he turned to engineering to make a life for himself.....

huge weight diff from formula wheels to gta wheels. also gta wheels are made in japan.
super light.
I made a post of me putting my gta wheels and formula wheels on a scale and being shocked by the diff.
from what I remember every pound of unsprung weight is like 10 pounds in the body.

From what I was told, optioning the crosslace wheels with ttops as a package, had something to do with offsetting the added weight of the TTops and keeping weights the same so recertification didn't have to happen..
The plastic ttops started somewhere in late 88 or 89, many TTAs have them and I know 2 for sure 89 formula 350s have them.
Yes, they are that much lighter than the 88-92 formula wheels (which is y most road race teams used that wheel plus break cooling), the 87 and older formula/ T/A 16x8 wheel is super heavy!