Guest

I remember these car new , so now I want another one but want to buy the
"right " one
I liked 88
But others say 89
I'm not a fan of the 90 for the dash
350 tpi with3:42?
Blue , red, yellow
Which are the most desired ruling out the 1 le of course

Remember desired

82RZ

In the car world, 'desired' usually means 'collectable' which usually means low production numbers.

Going from this presumption, a 1990 'drop-top' IROC would be quite desirable.

According to the White Book, 1294 were built. How many survive today is anyones guess.

scottmoyer

But, since he said he isn't interested in the '90 model because of the dash, that rules out the 90. The two most desirable years appear to be the '87 and the '89. There are many reasons for both. Based on that, you then need to go based on visual cues. The '87 rims and striping are different than the '89. The interior seat fabric/leather is different between the two also. If you want 3.42 gears, you need to get a 5 speed car.

camarosrock1989

iTrader: (1)

What he said ^ Just make sure it is a really nice one when you buy it. Cost a lot of money to fix them up.

Guest

Ive been looking at eBay for a while now
A lot of iroc owners seem to price them high and they don't sell
Example would be a 88 350 100k for 11k

Seems like some sell (low mileage high optioned car)
At 12k and higher
But the middle of the ground cars seem there cars are worth more

I'm looking for 88 or 89 350 red t top car black cloth interior

What were my options for those years

Why 87or 89 what about 88?
Need your input fellas
Thanks in advance

Newfie Iroc

iTrader: (1)

Go '89, 5.7, auto, hard top, in blue...... This is mine

Impaqt

iTrader: (1)

Look through Classifieds. Thats what I did.

Buy Iroc that is the in the Condition you can handle at the price you can afford.

Without knowing anything about your example cars, we really cant comment on the value or pricing.

Guest

Sexy!!!
I had a blue 86 years ago, black interior t top car
I loved it. Now I sold my 89 turbo trans am looking for a iroc
Personally I like the iroc better than the t/a
But I always wanted a TTA but after owning it I like the grand national better
And I like the iroc better than the TTA

So does 89 have more power?
What were the options available in 89
In 89 what wre the highest rear gears available?
And what rear Australian 10 bolt?

Guest

I'm looking at low mileage 30k or lower
350 stock red black interior
I see them from 8k to 15 k
Big swing in price
Mint of course

MY87LT

iTrader: (2)

1989 was the first year for the chip in the ignition key (Pass Key/VATS) So some extra security.

Guest

Any of our guys have pics of the 89 interior?
Seats that is?
Compared to 87 or 88

Edwardgp

1989 Blue with Black interior.

Guest

Pics?

camarosrock1989

iTrader: (1)

There is a really nice one here in CL i think it is a 88 Iroc, super clean with low miles. check out Tucson Az craigslist it is the original paint the flame red. His last price was $8500, i would pay the money for it if i had it. Here is a picture, they have pictures of the inside and motor in CL listing.

okfoz

So, you want an IROC-Z...

Here is what I would look for.
1) Pick your color.
2) 350, with the G92 (3.27 gear ) or LB9/M5 G92
3) Decide it you want An airbag, if so 1990 only
4) If you want T-tops 1987 & 1989 are most common, NA in 1990.
5) Best Performance would probably be 1989 or 1990

I would Avoid the L03 or LG4 if you want something with a potential of collectability...

John

Guest

Ok John break it down for me
What's a lb9/m5g92?
And what's a lo3 lg4
I'm laymans terms
Thanks

AmorgetRS

iTrader: (6)

LB9 is 305 TPI
M5 - Manual 5 speed transmission (the T5)
LO3 is a TBI 305, LG4 is a 4 bbl quadrajet 305

G92 is the performance rear axle, so for a 350 you get a 3.2x instead of 2.7x and for the 305 M5 it's a 3.4x instead of 3.08 (or whatever the ~3.0 9 bolt rear end ratio is). It makes a bigger difference then you would expect.

Guest

Awesome thanks for the education
What about the austrialian rear ?
Pros cons ?

AmorgetRS

iTrader: (6)

Pros - stronger
Cons - when it breaks, more expensive.

If you buy either a 87 or 89 with the G92 it should come with the 9 bolt (or as you called, the Australian rear)

Slater126

iTrader: (1)

Also bear in mind that 1987-89 LB9/M5 cars have a different camshaft than the LB9s with the automatic. The former has the good L98 cam. The latter has the mild LG4-style "peanut" cam. Big difference in performance in addition to the power sapping automatic.

Starting in 1990, LB9/M5 cars without G92 also had the milder camshaft.

scottmoyer

Guys, let's help him out here. We're throwing terms around that are common to us, but unknown what they mean to outsiders looking to learn.

L98 - 350ci Tuned Port Injection (top dog)
LB9 - 305ci Tuned Port Injection (2nd best)
L03 - 305ci Throttle Body Injection (3rd best) (base 305 engine for years offered)
LG4 - 305ci Carburetor (not available after 1987) (base 305 engine for years offered)
M5 - Manual 5 speed transmission
A4 - 4 speed Automatic 700R4
G92 - Performance rear axle

In 1987, all 350 based IROC-Zs came standard with the G92 axle, so the 350 came with all of the goodies. In 1988 and 1990, this wasn't the case. You could get a 350 based car with 2.77 rear gears. If you want the best performance 350, in 1988 and 1989, you need to find one with the G92 option code.

Now let's talk LB9 305. This is the second best option according to my statement above. It could be the best option if you get the 305 Tuned Port Injection, manual transmission and with the G92 code. In that case, the 305 and 350 were almost comparable in performance due to the manual transmission giving a 3.45 rear gear ratio vs. the 3.27 of the 350 based car. The engine remains 2nd best if you get the 305 Automatic.

A non G92 car will have the basic highway gears of 2.77 or in the later years, 2.73. The 1989 G92 car is different than the '87 G92 in that the exhaust is built with dual catalytic converters, which upped the horsepower to 240, where the '87 is 225hp with the single exhaust. A 1989 IROC-Z 350 without the G92 code will have 230hp.

chazman

iTrader: (4)

Actually, the 91-92 LB9s all had the L98 cam. The non G92 versions were restricted by using the L03 exhaust.


You can find something neat about all of the IROC-Z years. '85 and '88 had some one year only colors. '85 was the only year you could get an L69 in an IROC and it's LB9 got the L69 cam for that one year only, you could also get the Conteur interior that year. '87 had it's own unique interior. '89 had the best performance components available. Heck.....even '86 had the most powerful LG4 EVAR!

Find a nice one, and you can find a reason that it'll be the best one - for you.

cIaRmOaCrZo

WOW, thats the exact car iv been looking for. i keep trying to find an 89 iroc, blue, l98, black int, STOCK or at minimum factory paint and stiping. but can never afford one if i find one. then i found a busted up roller yesterday but it had been too far butchered, and too far to get. congrats on the car, i LOVE it.

Slater126

iTrader: (1)

You could be right, this always confused me. I deduced from these two websites that the non-G92 5-speeds in 1990-92 got the peanut cam:

https://www.thirdgen.org/tech-data

http://www.iroczone.com/2009/10/iroc...ters-guide/#90

The camshaft chart in the first link lists the peanut cam for "305 5spd / 305 AT" and the L98 cam for "305 G92 5spd / 350 AT." The latter link says that the "5000 RPM redline tachometer was used on the 305 CID (5.0L) TPI engine (LB9) equipped IROC-Zs, without the G92 performance package" for 1990.

So, putting two and two together, I figured the non-G92 5-speeds got the peanut cam and the G92 5-speeds got the hotter cam in 1990-92. Why would a single cat necessitate a lower redline, especially since all 1987-89 LB9/5-speeds had the single exhaust and higher RPM tach? Not saying I'm right but that's what my admittedly limited research revealed!

Slater126

iTrader: (1)

It's also interesting to note that the 1988-89 single cat LB9/M5 made 220 horsepower and 290 lbs/ft of torque, while the 1990-92 single cat LB9 only made 210 horsepower and 285 lbs/ft of torque per the tech data on this site. That also implies a weaker cam in the non-G92 LB9/M5 cars during the last three model years of the Third Gen.

navy02ws6

I'd recommend an 87...last year for the good wheels, and the only year you could get them with the L98.

chazman

iTrader: (4)

'90 was the same as '89 in regard to L98 and peanut cams. It was '91-'92 where all LB9s got the L98 cam. The non G92 versions got the entire corked up L03 exhaust, even the more restrictive 2" exhaust manifolds, which never were on any LB9 previously.

okfoz

Both Parts Catalogs call out the same Cam part number for all LB9 (305 TPI) and L98 (350 TPI) Engines from 1990 thru 1992. The L03 had a different cam.

What does this mean? More or less the replacement parts were all the same. Does it necessarily mean that they were the same from the factory? Probably yes, and possibly no. However do to the fact that other years were pretty clear on the cams and some cars got the peanut and others did not insomuch as they did not go to all one cam as replacements, suggests that they used one cam for all LB9 & L98 engines.

John

jermdm

You can look at my link for pics of an 89 seat and interior. I know there is different combos but mine has leather seats with adjustable headrests. I had an black 89 RS back in 1994 with red cloth seats with no adjustable headrests. The headrests were built into the seat back. My iroc has the 350 tpi but not the G92 pkg. Not a bad thing though. With the 2.77 highway gears, it still has alot of get up and go and at 65 mph, the engine is running around 1650 rpm which helps with mpg compared to a taller gear. You can look at this post that I posted about desirable years. Might help in your selection. https://www.thirdgen.org/forums/hist...able-year.html

Slater126

iTrader: (1)

Now that I'm really curious about this (for whatever reason), I sought help from the GM Heritage Center's Vehicle Information Kits, which you can get online here..

http://www.gmheritagecenter.com/gm-h...tion-kits.html

Naturally, the material doesn't list camshaft part numbers or specs for 1990-92 engines. But it does tell us about the exhaust systems. The material shows that the 1989 LB9/L98 single cat and 1990-92 LB9 single cat exhaust systems were in fact different, as Chazman said. They did have the same 2.5" branch, 3" main, and 2.25" diameter tail pipes. However, the intermediate pipes were different. They were 2.75" on the 1989 cars and 2.25" on the 1990-92 cars.

The diameters listed for the 1990-92 L03 exhaust are 2" branch and 2.25" main, intermediate, and tail pipes. FWIW, the same diameters are specified for the LHO V-6 system. So the only part of the L03/LHO system that was installed on the single exhaust LB9 cars was the narrower intermediate pipe, at least according to the GM Heritage material.

So maybe that was the reason for the lower RPM tach and lower power rating. Or maybe it wasn't. I guess the only way to be 100% sure will be to actually pull a cam out of an original non-G92 1990-92 car and see what the part number is. Any volunteers, hehe?

TTA1451

Autodynamics, try the Camaro White Book....loaded with info for buyers new to the F-Body Game........

Guest

Where would I find that ?

TTA1451

Pete, try places that sell books...its by Mike Antonick