Mississippi

So ever since I bought my car (95 z28 m6) I have realized its faster than a stock LT car should be. I have raced several stock m6 and a4 LT powered fbodies and always win by at least 2 cars. I always assumed that it was due to my car being well taken care of as it is a 3 owner car (two of which being old men the other is me) with an excellent service record. I thought that until o drove my buddies 99 WS6. At 90 his tach is only showing 2k rpms. Mine is something like 2500 at 90mph. Then I looked up some charts and realized that I have a 3.73 rear end. Now when I got the car it had stock everything. Airbox, muffler, cat, paper filter, the works. Both previous owners said they never touched anything except for maintenance. So it got me wondering if maybe some cars came with 373 from the factory? I know for a fact that it is not a 342 ratio back there and according to the rpm-mph charts I in fact have a 373. Just curious if I was lied to or if its possible that it is a factory addition?

Uwilllosetomy93lt1

Hehehe....3:73's not likely but, ya never know what GM might have left to throw in there. Sooo, my suggestion is to pull the cover off for a fluid change, then simply start counting. No lie's there bud!

1-kwik-6

If you do pull the cover and change the fluid check the edge of ring gear. It should indicate the ratio, (factory gear or not). I highly doubt they are 3.73.

Big Al

iTrader: (1)

Or you could just jack up the rear and count the drives haft turns.

Al 95 Z29

transbird95

iTrader: (4)

You sure it's not 3.23's? check your RPO codes for a GU5 that would mean 3.23's. They did put those in from the factory.

96lt1m6

iTrader: (31)

The ONLY way to find out what gear ratio is in your car is to remove the cover rotate the gear around until you see a stamped number that may resemble this:
41-10
39-10
You then divide the big number into the small number and you will get the actual gear ratio 41÷10=4.10
While you are there you can change the gear oil anyway.

speed_demon24

iTrader: (6)

It's probably just the tach being off which is very common. No 6-speed cars left the factory with 3.73 gears so there's no reason to think gm for some odd reason did it to yours.

justin hover

I'm at 1900/2000 rpm at 55-57 mph... 2500 rpm or alittle over 70-72 mph. At 90 I can't remmer but I know it's def. in the 3000's rpms with my 3.73s. So at 2500 rpm and at 90 mph you do not have 3.73s, that's a fact..