3.73 or 4.10

[03TahoeZ71]

I checked my RPMs @ 75mph yesterday, and I noticed that I'm right at 21-2200 @ 75mph (with a true speedo).

Does that tell you that I have 3.73s or 4.10s? (FYI: I have the tow package on a 4.8L)


Thanks again Jay!

Look in your glove box at the RPO code.
GT4= 373's
GT5= 411's

 

[Jay]

The tachometers on these trucks are off a little bit. 31.6" tires with 3.73s at 75mph corresponds to about 2080rpm. 4.10s would be close to 2300rpm at the same speed.

I'll assume you have a 2004 or older model, where 3.73s were standard on the 4WDs and optional on the 2WDs (3.23s standard on 2WDs). 05-06 model 4WDs could only get 3.42 or 4.10 from the factory, while 2WDs could only get 3.23s or 3.73s.

Denali's got 3.73s in all years 06-older.

 

[chip]

Look in your glove box at the RPO code.
GT4= 373's
GT5= 411's

The tachometers on these trucks are off a little bit. 31.6" tires with 3.73s at 75mph corresponds to about 2080rpm. 4.10s would be close to 2300rpm at the same speed.

I'll assume you have a 2004 or older model, where 3.73s were standard on the 4WDs and optional on the 2WDs (3.23s standard on 2WDs). 05-06 model 4WDs could only get 3.42 or 4.10 from the factory, while 2WDs could only get 3.23s or 3.73s.

Denali's got 3.73s in all years 06-older.

So check this out: Right after I posted this, I just happened upon a totally seperate thread just in time for this same discussion. I'll try to find it again, but somebody (forgot who....sorry!) posted up all the glovebox gearing codes. Mine is an '03 GU6 (3.42).

Thanks again guys! I really appreciate all your help!!

Here it is: http://www.tahoeyukonforum.com/forum/showthread.php?t=25387
.

 

[Rook1979]

The difference in mpg for these two gears is almost negligible... maybe 1mpg at most. The reduced low-rpm

Hey was wondering if a 2003 denali rear end will fit a 2006 silveado with tow package? Any help would be much appreciated! !

 

[Rook1979]

Can anyone tell me if a 2003 denali
rear end will fit a 2006 silverado w/tow package?