Ok, I am really confused as to my gearing. I used the method of going to 70 then checking my RPMs and got 2400RPM@70. So I say oh, must be 2.42s I have, except that was not an option in 84s. I am running the stock 15's and have a Z28 305 H.O. L69. Is the RPM@70 made for 16" tires or something? Did the previous retarded owner (who got an after market cruise control) also change the gearing in the rear to something obscenely low? I don't have the option sheet on me but I THINK I remember (3 months ago) seeing G92 which would make it 3.73s, but let me tell you it doesn't take off like it has anything other than 2.42s :-P So what do you guys think? 3.42s or 3.73s? I'm confused :-/

 

I don't think any third gen ever came with 3.73's. I am also pretty sure that the RPM@70 thing is for 16" tires. Also just so you know, the lower the number the higher the gear i.e. 2.42's are higher than 3.73's. I know it's confusing but that is the way it is. Hope this helps.

 

2400rpm at 70 mph in overdrive with stock 215/65R15 tires--the gears are 3.73. Yes the early thirdgens came with 3.73's and it sounds like that is what you have.
at 2400 rpm
16mph 1st gear
31mph 2nd gear
50mph 3rd gear
71mph 4th gear
http://www.f-body.org/gears/

The rpm at 70 in THIRD gear isn't that accurate of a method anyway. Third gear at 70 should be 3400rpm.

84 G92 is 3.73 gears. Which was usually included with the HO engine.
https://www.thirdgen.org/newdesign/tech/techdb.shtml



------------------
350 with stealth intake, holley carb, 470 lift cam. 700r4 with .5 boost valve, vette servo, tci lock-up kit, B&M megashifter. Richmond 3.73 gears, powertrax locker, timkin bearings, synthetic lube. Custom 3 inch single into 2 2.5 pipes. 1 1/2 drop springs, 1 5/16 solid front sway bar, 1 inch rear bar, custom subframe connectors, custom LCA relocation brackets. Kobel ground FX, currant red metallic paint. Lots of other stuff...
82camaro

 

Neat, that means I don't have to waste another $200 upgrading my gearing, just $100 on a posi unit to hold me over til I change my rear to a 9" to go with the new motor next year.

 

cool, never knew third gens had 3.73's, did they ever come in a posi unit? Would this bolt into a 91' rear end??

 

i think 83-84's came with the 3.73 posi on the 305 L69 with the manual transmission, and yes the posi and gears will bolt into a newer rear but you will need to use 26 spline axles, you can get 3.73 gears out of astro's and s10's

 

In 84 you could get 3.73's with the 4 cylinder, a coupe with a manual/Non HO/G92 option, a Z28 with a manual, a z28 with a auto and G92.
Inwo, you aren't looking at the SLP take off posi are you? If so, keep in mind you will need later model axles, bearings, and have someone install it(if you don't have the tools). In this case it might be better easier to install a powertrax locker. Cost is around 310 bucks and you can install it without removing the ring and pinion or any of the bearings. No special tools needed.


------------------
350 with stealth intake, holley carb, 470 lift cam. 700r4 with .5 boost valve, vette servo, tci lock-up kit, B&M megashifter. Richmond 3.73 gears, powertrax locker, timkin bearings, synthetic lube. Custom 3 inch single into 2 2.5 pipes. 1 1/2 drop springs, 1 5/16 solid front sway bar, 1 inch rear bar, custom subframe connectors, custom LCA relocation brackets. Kobel ground FX, currant red metallic paint. Lots of other stuff...
82camaro

 

I realize that most people do everything they can think of to figure out their gear ratio without removing the rear end cover, but I always say seeing is believing. If you pull the cover, your ratio should be stamped on either the back of the pinion gear, or the side of the ring gear, or both. It will be look like this (ex. 12:41). Then all you have to do is divide the smaller number into the larger number and you'll know exactly what you have. Also, one thing to keep in mind if you decide to go with the powertrax locker unit, they can be a little rough around corners. I run one in my 12 bolt in my '69 Camaro, and sometimes the teeth catch funny around corners and cause a bang from the rearend. It's never damaged anything, but if you're more interested in a smoother operating unit, a posi is the way to go. However, you can't beat the powertrax unit for maximum two wheel traction in a straight line. The only thing more effective would be a spool, which isn't practical at all for street driving. Just my .02 cents worth.

------------------
89RS w/350 TPI; 69RS/SS w/450 HP 350/Muncie 4-Speed "Too weird to live, too rare to die."