First off, I really like the idea of keeping the stock 3.73 gears.
I know this might not be a popular idea (4.10's, 4.10's, 4.10's) but check this out.......
with a supercharger and 33" or 35" (since 34's are so d**n hard to find)
I 'm hoping to signifigantly increase off the line acceleration (0-60mph) while turning
approx 2000 rpm at real freeway speeds (i.e. 70-80mph) instead of the 2700rpm
with the 245/75-16's for better than stock highway fuel economy (long trips)
PLUS! be able to light-med off road occasionally.
so the plan goes like this:
1. Radix Supercharger
2. TOG Headers, Borla Cat Back Exhaust
3. Transgo Shift Kit, Yank high stall converter
4. Stock Rear End (AAR 9.5" 14 Bolt) with stock full locker
Note: I could always upgrade to the AAR 10.5" if it breaks.......
5. Stock height with 33" tires (285/75-16 or 285/70-17)
or
Rancho Lift with 33" tires (33x12.50-16 or 33x12.50-17 or 325/60-18)
or
Rancho Lift with 35" tires (35x12.50-16 or 35x1.50-17 or 325/65-18)
What would this run in terms of $
Lucky me, I got the approval code from the wife for a specified $ amount
and I'm just wondering what you all think of the above senario.
I really like the looks of the 18's as they would let me run a big brake kit too.
BUT!
In terms of light-med offroading how do they hold up?
does someone have some experience with their offroad worthiness?
It wouldn't be worth it to me, to go offroad once and mess up a rim, on
the other hand how agressive can you get with a crew cab w a 6' bed?
any advice is appreciated....

 

What is this going on ... ?

 

oh yeah, that might help

2003 1500HD 4x4 Autotrac, 6.0l, 4l80e, AAR 9.5" semi-floating rear end w/factory locker, AAR 9.25" front IFS.

 

any advices at all??

 

for offroading, is a stall such a good idea? i dunno much about that

 

I would go with the 4.10s still. You are talking about a big tire on there, so that will help. I would stick with a TT2600, nothing to aggresive, but it has a really nice feel to it. I had one in my Z71. Other than that ... I think you are on the right track.

 

If you keep those 3.73s and 33" tires you can go 70mph at 2000rpms. Well, theoretically. Ok you can go 70mph at slightly more than 2000 rpms.

The HD trucks have a .75 4th gear right? If so then these numbers are accurate.

With 4.10s and 35" tires you can go 68 mph at a slight bit more than 2000 rpms.

So its up to which tires you want to run.

I'd save the money and keep the 3.73s, but don't get the 35" tires, or its gonna be slower.


Keep in mind though that while bigger tires might give you a bit more mpg on the highway, they will lose you mileage driving around town and in stop and go, -bigger rotating mass.

 

Larger tires and a lift will cost you a couple MPG no matter what the gear ratio or RPM's you turn on the highway. It's just more mass to keep rolling plus you are pushing more air by sitting up higher. I'd say keep your stock gears at first. If you don't like them, swap out to 4.10's or 4.56's later.

Your semi-floating 14 bolt is plenty tough for what you want to do with it.

18's? They would probably be ok for light wheeling. It would come in contact with rocks and mud more so than a 16" rim would, but it may not be enough to make a difference. I've never run 18's off road though.

Sounds like you are planning a badass truck!

 

Going to take my truck with the TT3000 to the beach soon. We'll see how she behaves in soft sand. I think she'll be OK.