ChickMagnet

To my delight after looking at the original owner's invoice for the second time, I realized that it was equipped with the performance axle ratio. Is that anything to be happy about over the standard axle ratio, or perhaps I'm getting excited over nothing. I honestly thought that all stock C4s had the same gear ratios. According to a post, a 94 performance axle ratio is 3.07, vs the standard 2.59 - So I'm wondering if this was the same for the 91...I have an auto o/d trans by the way. Another option listed was the engine oil cooler, nothing to be ecstatice about there though though

corvetteronw

There were 4 different ratios for 1991. 2.59:1, 2.73:1, 3.07:1 and 3.45:1. The latter was only available with manual transmission and ZR-1.
There were 20,639 Corvettes produced for 1991. 3,453 of them came with RPO G92 Performance Axle Ratio and 7,525 came with RPO KC4 Engine Oil Cooler.
Just as a note: There was only 1 automatic-optioned coupe that came with RPO Z07 Adjustable Handling Package. Any chance that you have it? If you do, then you have got a rare one indeed!

hardlight

I have one of the 91 Z-07 automatics. Z-07_Freak has kind of been keeping score, last I heard there were at least 4 of the 732 that had the automatics.

Casethecorvetteman

Itll be 3.07:1 and i think its something to be excited about, cause if its a coupe (im not sure, but i think verts had the 2.73:1), the 2.59:1 ratio is rather poor unless youre always on the highway. Dont know what the 2.73:1 is like but i cant see it being much better than a 2.59:1.

vader86

3.07:1. Its certainly the best gear suited to the L98, and you shouldnt ever change it.

Tranzor

The 3.07s do seem like they'd be the perfect gear for the L98. My '91 is of the 2.59 rear gear variety, and it did seem rather sluggish... the torque converter and the shift kit I installed help, but I'm still planning on switching it to a 3.07 when I get my rear diff serviced in the next few months or so.

ChickMagnet

It is a coupe, so I got the 3.07 ratio, which explains why this car really pulls I don't have the adjustable suspension package though I got the Group #1 option which includes -

Electronic Air condtioning,, six way power driver's seat, bronze removable roof panel, black leather seats, delco bose music system, low tire pressure warning(like I really need this), six way power passenger seat, engine oil cooler, ca emission requirements, performance axle ratio, p275/40 ZR-17 S/B Radial B/W - of course I now have y2k wheels and different tires.

3,453 made...hey that's not that many to me...and I figured I had the same axle ratio as everyone else, so I definitely have a nice warm and fuzzy now

Z-07 freak

Four confirmed, with a strong possibility of a fifth.

vetteman42

You should know that your HP rating is 250 / 350 torque with the G92 - perf axle ratio 3:07 assuming you are stock. Less restrictive mufflers were used with the 3:07 ratio gear.

I have the same drive train in my '91

SAVE THE WAVE !!!

ChickMagnet

Chopper57

Just wondering if ZO-7 freak is still on here.
I came across this thread and was curious if the count was still at 4. I definitely also have a ZO-7 with the 4spd auto OD trans.
I have only owned this car for about 8 years, so that would be well after the last post on this thread, so I don’t know if mine was previously counted.
This one should be easy to distinguish, as it was modified by John Lingenfelter directly from the factory, before it was delivered to the dealership for the original owner.
I purchased this car from Ken Lingenfelter, directly from his “Lingenfelter Collection” in Brighton Michigan.
Thanks for any response, or updates.
Dave W.

Sabre34

ZO-7 freak hasn’t been active on the Forum since 2014. Thread closed.