anyone know of any good detailed articles on swapping in3.73 for 2.73 in an 87 iroc w stock posi rear?looking for how to and list of all necessary parts.

 

https://www.thirdgen.org/forums/tran...axle-gear.html

The link is for a 10 bolt and you've probably got a 9 bolt, but the principles are the same.

 

[quote=bcmag;4775650]anyone know of any good detailed articles on swapping in3.73 for 2.73 in an 87 iroc w stock posi rear?looking for how to and list of all necessary parts.[/quote

I don't know if I am reading this right.

You want to swap a 3:73 for 2:73 gears?
Or you have 2:73 gears and would like to put 3:73 gears in your differential?

In a 2:73 differential - which is a #1 carrier - you would need a spacer between the ring gear and the posi carrier - not a good idea.

If you had a 3:73 gear set and wanted to go backwards to 2:73 - you would need a different carrier - because the 3:73 is either a #2 or a #3 carrier and they do not interchange.

I have never seen a 9 bolt rear end.

The S 10 pick up, G body - Monte Carlo, Pontiac Grand Prix, Buick all used the 7.5 carrier.

Except the Grand Nationals and Pontiac 2+2 used a 8.5 inch ring gear.

 

oops going from2.73 to 3.73.sorry

 

There is a special thick 3.73 gear that is made to fit the 2series differential in the 7.5 10 bolt. This is the only rear end that has these gears available for it. You will also need a good installation kit. Don't buy cheap crap or anything from Summit or Jeg's. They don't have good installation kits.

 

thanks for the info guys big help!I'll let ya know how i make out