I ran the RPO code on a junker Black Firebird and came up with a 3.73 axle ratio. Now does anyone know of they made a 3.73 open rear end? If they didnt I guess that means I found a 3.73 Posi in a junkyard haha.

 

A: Yes. My 87 Aerocoupe has one (for now) and plenty of 83-85 L69 F-bodies could have gotten them. Posi was around $100 option and dealer-ordered cars usually get "bling" options vs. functionality options.

If it's original & has code G80 it's posi. If it doesn't, it's not.

 

yes 3.73 open is common, i have had two both under 84 F body, a camaro and a firebird

VERY common lol


i need to find another for the 82 trans am so i can dump the junk original 2.73 open axle under it,

 

See I have a 2.73 open in my 89 Formula and its kinda holdin me back. Im looking for atleast a 3.23 posi. Thanks for the info yall, I think its crazy they'd put a 3.73 open how could you hook the tires up? Hell I spin with my 2.73 haha.

 

In snow, you rock the wheel back and forth

In my case, I'll be swapping to a posi 8.5" soon enough.

 

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Some of the early 4 bangers got 3.73's with out posi.

 

Are there any 4.10-11 open rears that would fit a thirdgen. Maybe a s10.

 

Yea I found that 3.73 out of a 4cylinder bird.

 

a 3.73 posi in my car under my name on the left.
a 3.73 open in my 87 Aerocope
3.42 open in (2) 1983 SS's
a 2.29 open in a 78 Monte

All 7.5's (7.625 in the 3.73s)

and a 3.73 open 8.5" that I need to install and put a posi in.

 

DOH! Double post.

 

Yes some of the 4 cyl stick "S" series trucks did have this gear. But if your going to do the swap, be sure you already have a 3 series carrier.

As for the 3:73 oepn rear...

Alot of 85-88 Monte SS's came with a 3:73 open rears. I replaced mine in my SS, with a Auburn posi for a 84 Z28 disc rear.

 

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What are you looking for? I don't know what's in stock right now but will be @ the parts cars tomorrow probably.