ok mostly everyone when changing gears they either go with 3.73s or 4.10s,
i was sold on 3.73/w true trac, just because i do alot of highway driving, but what about 3.90s is someone running dem'? whats the diifference between these gears? because iam going to buy a truetrac/w ??? gears... for my early xmas gift 2 myself...
i have a 03scsb5.3, bolt ons & wheatley tune

 

difference in what? There is about a .17:1 difference between the two.

 

difference in driving, MPG's, performance...

 

a little bit. Your rpm will change at cruise about 150 rpm. It's a tiny difference man.

 

if your doing the swap just go 4.10's

 

Help me decide what gears should i get? Do 4.10s really lower mpg i just did lonngg trip and i was just getting about 25mpg's...and how does it really affect highway driving?

 

4.10's because if you don't like 3.73's you'll want to change them again.

 

Depends on your tire size .......... stock height tires 3.90 is nice ........I have 31.6" tall tires and installed 3.90 gears ....wish I went 4.10 that extra 150-200 rpm would be perfect when towing allowing my TC to stay locked more .......... if you go 4.10 and too much rpm you can always go taller tire .............. my mileage in city got better, Hwy about same at 70mph at little less going faster

 

ok well i have i think i have 30.5 tire, so what would be a better setup 3.73s or 4.10s?

 

You'll have to decide that. Personally I'd go with at least 4.10s maybe 4.30s but everyone has different driving styles and habits.