Some of you have probably seen my posts about the new "mystery machine" the 1999 Z28 1LE. I bought the car with 8k miles on it for 12,800. Thought i was getting a steal. Well just to fill you in. The car was once upon a time heavily modified. I didnt notice test driving the car how horrible the rear end sounded when i bought it 3 days ago. Anywho, i took a few friends for a ride today and we are convinced that i dont have 3.42 gears. However, i needed more proof. I took the car to Quick lube to get everything changed and checked. The mechanic there who is a very nice guy whos been doing work on my cars for the last 2 years let me go down in the pit. The Rear end on the car is Black, no rust, looks brand spanking new. My 1LE rear sway bar is gone, stocker in place. Front sway bar is not there. The Motor mounts and A arms have rust, but the part that connects the A arms is still black, looks new. Moving on, i decide to take it to the track tonight to see what it could do. The rear is making news, but it feels strong so i said what the hell. Ok, so my old 99 SS went 8.8s stock on a 2.1 60 ft. Best i got tonight was a 92 @ 83.5 mph. (1/8th) But heres the kicker. I went through the traps at 5k RPM in 2nd gear obviously something is wrong. So i only do 2 passes, decide to call it quits, the car is just a dog down low, a beast up top. So im cruising home and i see one of those things that tells you how fast your going. It says 56, my speedo says 47, hmmmm, a few minutes later i catch up to a state trooper. Im doing 65 in a 70, or so i think. He seems to be going slower so i gradually pass him, im about 4 cars up on him and i speed up a little to the speed limit of 70, he comes up beside me real quick and flick his lights on for a sec and then falls back still in the other lane. IM thinking now that i definetly have a un calibrated speedo. So in conclusion. Do you guys think i have a automatic rear end? 3.23? 6th gear is a dog. Hard to maintain speed without putting hte gas down. you know, at like 1500 RPMs im strugling to do 70

 

The thing that connects the motor mounts and A-arms is the k-member. In my experience they dont rust as quickly as the mounts and arms.

With 3.42 gears, 70mph is about 1500rpm with the stock 25.6" tire height.

BUT, if you went through the traps at 80-ish, you might have 2.73 gears in there.

If you have the stock size tires on the car then you should try this. Drive by the radar sign at 75-76 (its reading, not yours) in 4th gear. 2.73 gears should be about 2700 rpm, 3.23 should be about 3200 rpm, 3.42 should be about 3400, and so on.

Eric

 

Thanks, im removing the cover in the morning. I will know for sure then. but good idea. It Cant be 3.42's though. this is my 4th 6 speed Fbody, and i ALWAYS shift to 3rd before hitting the trap at the track.