c4rokuez

I've been looking at C4 Vetters and found this one in Mound City MO.

https://stjoseph.craigslist.org/ctd/...641630802.html

Stock #: P104883
VIN: 1G1YY338XM5104883
Year: 1991
Make: Chevrolet
Model: Corvette
Trim Level: Base
Mileage: 103,980 miles
Price: $6,000
Exterior Color: White
Interior Color: Black
Engine: 5.7L V8
Transmission: 4-Spd 4L60 Automatic
City MPG: 0.0
Highway MPG: 0.0

103k miles.


I've started reading about C4's and when I read this thread

https://www.corvetteforum.com/forums...or-the-c4.html

"Any year as long as it's a manual or a 3.07 or better geared Automatic. You won't have as much fun with the 2.59 gear. "

from user 84wuzmy1st .

Is there anyway to tell this 2.59 gear vs 3.07 gear from the information listed here or do I have to call the dealer to get the RPO Code?
I'm also open to hearing what people think about this C4 no matter what your opinion is.

AgentEran

you can look at the rpo codes..
G44 = 3.07
GH0 = 3.54
GM3 = 3.45
GT7 = 3.33
GU2 = 2.73
GW4 = 3.31
GM1 = 2.59
​​​​​
As for the difference between them all.. 2.59 is def the least desirable in terms of performance but is still enjoyable and gets good mpg. 3.54 is the best performance stock ratio and is only available on m6 cars.

PatternDayTrader

I like the 2.59 gear. In overdrive at 120mph the engine is only spinning about 3k rpm. It all depends on what your doing with the car.

AirForceOne!

I like the 2.59 gear. In overdrive at 120mph the engine is only spinning about 3k rpm. It all depends on what your doing with the car.

c4cruiser

The standard rear end ratio for that auto trans convertible should be 2.59. The only available gear option for a base convertible with auto was 2.73. It might be a help to call the dealer and ask them to check the SPiD labe for RPO GM1for the base gear or RPO G92 and GU2 for the optional gear. RPO G92 means the car is equipped with a "performance gear ratio" and there will be another RPO code that will show a specific ratio.

Newtomevette

According to the code on the inside of my console lid, my'94 coupe has the 2.59 gearing. She's not exactly a slug though, so I'm happy with her. Although I can't help thinking maybe some previous owner swapped it out for a 3.07... not sure how I'd tell that. Either way puts a big smile on my face every time I get behind the wheel.

Kens94

Polo Vert

I swapped the diff in my 94 vert for a 3.07 unit. Did the work myself and the car is much more fun around town zipping between stop lights. It still gets 25 mpg on the highway so I have found no real downside to the swap. Only unforseen problem I had is nobody near me has any equipment to recalibrate the speedo. Had to buy a Hypertech programmer and do it myself.

cv67

103 k is low miles?? LOL
Forgot thats CL...

Car doesnt look bad at first glance, like anything you need to get it up to temp, drive it, try all the electronics out.
The proveribal spin around a couple blocks wont tell you enough about the car.

vader86

Not going to have 3.07 in that car, but get the RPO codes that start with Gxx to confirm what is in it.

it is an L98, so it won't be a dog off the line like an LT1 motor will with that gear

FASTAZU

I would be more concerned about the cars condition.

vette196

I resemble that remark

65Z01

To verify rear gears
-jack up the rear
-rotate a rear wheel and count drive shaft rotations

If you want a little more off the line install a 2,000rpm TCC. It will really improve launch and still be very drivable on the street/highway.

TA

The 2.59 rear isn't actually that bad in a TPI car. When my 91 was bone stock (with a 2.59 rear), it went 14.00 in the 1/4. With bolt-on mods only I had it down to 13.35 with the same rear. Even with the 2.59, I regularly saw short times in the high 1.7x to the low 1.8x range. Not too shabby for the "highway" rear.

mark970

39% of 1991 Corvette auto's had the G92 G44 option so your chances are decent. I've had both ratios in my Auto C4's and its night and day difference from stop light to stop light. I wont buy an automatic C4 without the G92. Just my two cents...