if you have a G80 code then yes it is do the axles pop out from the outside without removing the diff cover??if so then you have a G80 rear end

 

Well I did not look in the glove box but I did try the VIN decoder and it has the folllowing listed for my truck:

RPO Description
GT5 Axle, Rear, 4.10 RatioR(GT5)
G80 Axle, Rear, Positraction, Limited Slip Positraction L/Slip R/AXL(G80)

I will check the glove box codes tonight and see what they say and compare it to the info from the VIN decoder listed above.

~GOD BLESS~

john

 

Well I finally managed to remember to look in the glove box for the rear end codes and they appear to match what the VIN decoder said the truck has. I found these two codes among the multitude listed:

GT5
AND
G80

So is that a 4.10 with posi?

~GOD BLESS~

john

 

Well, its not a true posi-trac. Limited slips will only spin one wheel and when it starts to slip, it will spin the other wheel, where opposed to the true posi-tracs that spin both wheels all the time. Limited slip I guess is a variation of posi-trac, both wheels can and will spin, but unless one is slipping, slick surfaces or burnouts, only one wheel will get power to it. I think GT5 is the 4.10s, but you mentioned earlier that 70 mph is 2250, and that is 3.73 gearing. So the previous owner(s) may have done a gear swap, especially if they used it a lot and never did any heavy towing.