digital

Is there a way I can tell if Chevy installed posi in my 00' Silverado 1500 Ext-Cab LT?

Thanks,

6gear

It should have a G80 code on the sticker in your glove box. It is usually followed after your gear ratio of GU4, or GU6, or GT4.

nativetexan

Nah, just power brake it and see if both are turning. More fun that way.

digital

Got it, there is the G80 code followed by GT4, what is GT4?

camman

that should be the gear ratio im not exactly sure what it is probably 3.42

Mort

GT4 = Rear Axle, 3.73 ratio

budhayes3

iTrader: (19)

I have the G80 code, and my window sticker lists it as a locking rear differential. Did/do these trucks come with a limited slip, or has that been replaced by the locker? Sorry about hijacking the thread.

digital

Hey thanks for the input fellas...

Another question I have is regarding the tune I'm about to get...I want to find out about eliminating Traction Control to light up 20'' wheels with a Whipple blower... what is a good/safe amount of TC to remove without hurting anything like the tranny, etc....

I guess this is a two-part question, also what shift-firmness should I be aiming for?

race495

So is the GU6 a 3.42?

6gear

GU4=3.08
GU6=3.42
GT4=3.73

The G80 is what they call a Gov lock, it acts as a open differential untill one tire turns I believe about 100 rpm's faster than the other and then a swinging weight causes both axles to be locked together.