O.K. there's the deal, I have been wondering about this for a while and I know there are people out ther who have seen this and can back me up.

Please read this before putting in any closed minded comments.

I have two 94 Z28s with A4s they were both built in 11/93. I have removed the rearend gears in each to put in deeper gears and they had 3.42s in both cars. I am sure it is from the factory.

The entire rear ends are 3.42 because they have the 3.42 stamped on the pass axel shafts too. So not just the gears were changed.

These cars were totally unmodded when I bought them. Not even a CAI the one still had the origanal plug wires. WEhat I'm saying is the previous owners wouldn't have swapped rears for the hell of it.

I bought these cars two years apart and it would be a real coinsidence if I got two cars that were totally stock except someone put in differant rears.

I was wondering if others had found this and maybe GM had run low on the 3.23 rears and sustituted the 3.42s. Like they ran out of 6-speeds and it wasn't and option for most of the year. They do have the GU5 code in the glove box.

Anyone who has one of these cars please speak up. I know they are out there and I would like to show it was a fact not a myth born in my head.

Thanks all.

 

I've never heard of that, but GM always gives us a few surprises. I've owned a '93 Z28, as well as my current '97 WS6, both had GU5, and both had 3.23 gearsets.

 

Sorry man, but 3.42 were only avail in 1995 for autos. GM plans stuff out, like they dont mess up really on things like that. They know they will alot X amount of six speeds, and X alotment of atos. They dont really mix and match parts. Like "oops, this car had a red interior but we ran out of red setas" "ahh just throw in a black one, they will never kow"

How ever, these cars had leaky torque arm problems, my only guess would be a dealer changed the rear out. But other than that, it can;t be factory.

 

Well their brochures DO say that if an option is not available they can put in an upgraded option without telling you and they did run out of 6-speeds in 94.

 

Also, Most people on here have been telling me that 3.42s were not an option for ANY Z28 A4s after 93.

 

I believe it could be possible to have GM do something wierd like that at the factory. MY blue 94Z came with an LT1 out of a 94 vette instead of the stock 275hp camaro LT1, and GM verified this saying that it was "a special order." and thats all the more they would tell me.

 

I always was for sure that no Auto car came with 3.42's from the factory. Only 2.73's or the performance rear which was 3:23's. But yeah never know, just because somebody did not mod the car does not mean that the dealer could not have done some swapping on warrenty work.

 

Uhhh...From what i have always read, the engines themselves are exactly the same, and have been since the F-body's top line engine was the L98, the difference in power comes from the L shaped air induction tube, and more restrictive exhaust manifolds. Only. And it is not physically possible to put Corvette LT1 exhaust manifolds in an F-body, they will not clear the steering shaft(which is much lower on Vettes) and the intake obviously does not work...But feel free to correct me if I am wrong...

BTW, was it the salesman, or the mechanics that told you this?

Now back in "the day" when Pontiac and Chevrolet had different lines of engines(like the 455 vs the biggest offered in Camaros, the 396) that was most definetly possible, and happened often(god, QC was next to impossible in those days) And did, in my Mother's old 1980 Lesabre, it had a 4bbl 455 Ponco in it, with paperwork to prove it.

 

Well i think it would be very possible,i have read that there were rumors that GM built a few third gen cars with the TPI 350 with a 5spd but it was never advertised or on the opion list.Also it was said in a book i have on camaros that the TPI 350 was released in very small numbers a year before it was made a option and also that some GM executives were given 82 pace car replicas with all aluminum 350 engines with a 5spd.These of course are rumors that i have read in books so i would'nt say that they are true.

 

I have a feeling that you were looking at this and thinking it said 3.42 when in fact, that is not what it is saying. Count the gear teeth if you want to be sure.

Since you are the first person I have heard of bring this up, I have my doubts of it's validity. (not flaming you)

Also, I don't recall ever seeing a gear ratio marked on an axle. Don't know why they would do that.

 

Ya know, now that you mention it, wouldn't the housings all be the same anyway? Why would there be a difference?

 

I dont think the vette 350lt1's and the fbody lt1's are the same,

vettes got 4 boltmain blocks and fbody's got 2 boltmain blocks, vettes also have different oil pans and a few other things,





where did u read 3.42 at? i got 3.23 and i always wanted 3.42's it'd be real cool if i already had em.

 

while we are on the subject of Vette and f-body diferences, what is the diff between "2 bolt" and "4 bolt" engines. I have heard that the vetted had 4.

Not sure if the term are correct terms or not. LOL I know its a Newbie question, but I'm a rotary guy so thats my excuse

 

You're right, I've spent too much time in LS1land.
But nothing that will make the power difference, besides what I mentioned. For the dealer to know the difference, they most likely would have had to pull the oil pan.(which would not be the corvette pan) and look at the mains, and know that the Camaro's and Firebird's have the 2 bolt mains. I don't know too many salesmans that would know that...However, I have heard many a salesman say "You know, that one has the corvette motor in it. That's not very common." right before I walk out the door.

 

for those who want to know about the lt4:

http://home.tir.com/~steveher/lt4.html

this site is awesome, it explains everthing that i know of, and then some. very informative

as for the gears, the guy said he saw the stamped rear housing and axle, not on the pinion, and not on the gears, the axle. mine says 2.73, and i know they are 2.73 because i rotated the tires 2 and 3/4 times and the driveshaft only made one revolution.