[67ChevyRedneck]

Yes, I am 100% sure. I even just went outside to double check both my trucks. The codes are the same for all GM trucks.

GU4=3.08
GU5=3.23
GU6=3.42
GT4=3.73
GT5=4.10
HC4=4.56

G80 - locking differential

Both my Silverado and S-10 have the GT4 code, 3.73.

Originally Posted by chevy2racr

Redneck - you sure its 3.73 or whatever you said rear? mine was 2.2 auto reg cab short box stock and has the little 4.10 or 4.11 or whatever around there, not a 3something gear. wouldn't mind the 3.73 posi my buddys xcab 02 sonoma has now that mines got a small block...

What you said makes sense, here's what I found from an S-10 forum. For the 2.2L reg cabs, the 5spd got a 3.73 and the auto trucks got the 4.11.

The following are for the 2.2L 4cyl

2.2 4cyl- regular cab LS - manual tranny/3.73
auto tranny/4.10

extended cab LS- manual tranny/4.10
auto tranny/4.10

regular cab xtreme- manual tranny/3.73
auto tranny/4.10

extended cab xtreme- manual tranny/4.10
auto tranny/4.10

The following are for the 4.3L V6

4.3 6cyl- regular cab LS- manual tranny/3.08
auto tranny/3.42

extended cab LS- manual tranny/3.08
auto tranny/3.42

regular cab xtreme- manual tranny/3.08
auto tranny/3.42

extended cab xtreme- manual tranny/3.08
auto tranny/3.42

Positraction is not available on the 4cyl engines

Positraction is available on either the 6cyl manual or automatic transmissions.