I have a 1979 Z i Love my car but i am running a 4:11 rear end (i believe) with a 4 speed tranny. When i am on the hiway running 65 i am at over 3000 RPM. I believe i am looking for a 3:73 rear end. Would a auto Z28 have the ratio in it? And is there any axles i can find stock with a posi 3:73 and disk brakes that will bolt in.

 

well if you want better cruising gears, you could also go as high as 3.52 but with your 4 speed tranny you should still do pretty good with 3.73, if you dont drive too much on the freeway

 

wow thats some rpms at 60. u may have some 456s in there. i agree with jason, 373 or higher. i think the next is 342s but im sorta out of my area with the second gens.

 

they didnt have any stock 3.73 gears for the late 2nd gens..the highest they had was i believe 3.08 that came stock but you can get a rear end from a 1st gen with 3.73 gears and have it adjusted a little to fit yours or just buy a new one with posi that will cost over 1k

 

I put a 1978 Trans Am complete rear end into my 71 Camaro, and it had 3.31 gears. Used everything from the TA including the sway bar, which is much larger than the optional swaybar of the Camaros. It bolted right in, and I think the only change was the U joint on the rear of my driveline. The new rear end used a larger U joint, so I installed one of those adapter joints to mate my driveline to the larger yoke.
I can cruise along at 60 at around 2,200 rpm's.
There are no bolt in rear ends that will have disc brakes on them. Unless you're lucky enough to find one of the rare Camaro rear ends that came with optional rear discs. Very scarce and spendy too!
But there is a easy bolt on option that I did to mine. Not discs, but 11" drums and backing plates from a Impala. Cheap and easy to find and install, and it gives you much better braking with more surface area.

 

What tranny and engine were you running. That is about what i want to be running cruzing on the hiway. How is the low end. Can you still make a smoke show in 1st with the new axle

 

are you running a 4 speed BB427?

 

I'm running a .040" over 427 BBC. Runs about 465 HP, and I'm running a highly modified turbo 350 manual shift, with Corvette clutch pack, and Transgo kit. Yes, it will make plenty of smoke through 1st and 2nd, and downshifting will lock up the rearend if I shift a bit too high rpm's. It will also easily break them loose from around 20-30 mph rolling.

 

what the heck does your modded tranny have in it to only have 2200 rpms at 60 with 3.31 gears, i do 2000 or so with my stock 2.52 gears lol

 

Nothing in the tranny to make it run less rpm's. Not sure why you would be at 2,00o rpm, my old 2.74 gears that were in the car when it was new would run around 1800 at 60, so I'm puzzled at your rpm. Maybe your tach is off a little?