According to the auction....

The diff will only work with 3.23 or higher... So 3.08s might not work.

I think the difference is that this is a series 3 instead of a series 2.

According to the Auburn website:

Special Note: GM 7 5/8” applications use (2) different tone wheels depending on the differential case series.
3.08:1 & down gear ratios - Series 2 Case
3.23:1 & up gear ratios - Series 3 Case[/align][/align]This is most likely for Auburn made parts, but still...[/align][/align]Maybe the guy got it wrong and it's a series 2?[/align][/align]If the shop has a 3.08 sitting there, ask them to slide it on the new one, and compare, to see how it sits...[/align][/align]3.08 should have more metal in it.[/align]

 

I do remember reading that you could not get the G80 without a certain gear ratio...

 

For strength reasons? My options for the G80 are 3.08's or 3.73's but I really don't want to swap out front gears, too. I can do the 3.08's and lose 4WD (for now) for $50 plus his cost to put them in.

OR I can order/find new 3.42's and buy a spacer and still pay his cost to put it all in.

3.08's are cheaper in the short term but more expensive long term.
3.42's are more expensive in the short term but cheaper long term.

BUT if it's a strength issue where for some reason a certain gear ratio can't handle the G80 then it's back to the drawing board.

 

I don't think that's an issue with it... But, if you plan on getting bigger tires... I'd reccomend the 3.73's, lol.

I don't think it's a strength issue... I haven't really seen a gear limit for the G80, other than the obvious size constraints...

I'd reccomend going with the 3.42's... You might even be able to find one that fits properly without the spacer...

 

No, I do not believe that it is a strength issue either, but rather one that the G80 was not offered with that high of a ratio (numerically lower). For some reason it sticks out that 3.42 is the highest ratio that the G80 was offered with, but I could be wrong...

Maybe I missed it, but what gears do you currently have?

 

Currently have 3.42's (GU6). If I could find 3.42's to work in a 2 series carrier without a spacer that'd be perfect.

 

Might have to work to find 3.42's for a series 2...


Should've just went for the ZR2 axle and put 3.42's in it, then the rear axle would line up with the front

 

Is there anyway to identify what I bought by the stampings on it? I've said my piece to the guy but I want to have correct information before I tell him he incorrectly listed this part.

On the non-ring gear side it has "049-1" and in smaller typeset it has "18 F5" and possibly an "H" directly opposite from the 18 F5. The ring gear side has a 4 stamped into it.

 

No idea about the stampings on the locker, but I would go with 3.42 or 3.73 gears (all 3.08 gears might do is help increase gas mileage, but the 3.42 and 3.73 will have more torque to the wheels).

 

3.08s would actually hurt city mileage a good bit... And highway mileage would only get better if it'smostly flat...The Blazer is kind of a heavy vehicle... 3.42s or 3.73s would work best for lots of city driving...


As for the fact of the matter... It's a series 2, since it does NOT support the gears that he has listed unless you get specially made gears for going from a series 2 carrier to fit a series 3 setup.