I know i've seen this somewhere before but I can't find it now[&o] hopefully someone has a link or short and sweet answer to solve my dilemma.
Ok I just picked up a 3" body lift kit, new leaf springs (4 leaves per pack versus the 3 that were stock), and 2.375" shackles (1.5" t-bar crank is a given here) for my 94 now is where i'm having issues I'm going to try like mad to fit 33's under it but my truck came with RPO GU6 (3.42 gear ratio) now i'm certain i'll need to regear when i do these tires (both front and rear I know) so my question is what would be best to maintain as close as possible to my current mpg without a big sacrifice in power? (I do understand that its very unlikely to keep numbers like I have stock but im looking for a happy medium here)
I was looking Here and it would appear at highway speeds 3.91 would be really close to factory as far as rpm's go but im unsure what it would do to my mpg? any input, suggestions, advice?
At this point it's entirely possible i'll end up just sticking with 31's so I dont have to worry about rubbing/travel issues but i'm looking for as much info as possible before making a final decision.

As always thanks in advance for your help.

btw move this if you feel it fits tire section better but since it was a gear ratio question I thought driveline area was a good place for it.

 

If you are going to stick with 31's, your 3.42 gears should be decent. If you were going to go with 33's, you would probably want to step up to 4.10's. Turning 33" tires can be a chore for the motor and anything you can do to help in the final drive ratio helps performance.

 

Thanks Kyle at least now I know what I'm getting myself into before i actually get into it, appreciate it.

 

No problem!

 

Kyle is right, besides, I don't believe you'll be able to find 3.91 gears for our trucks. I currently am running 33s with 3.73 gears (stock ZR2 gears) and don't have much to complain about. A little sluggish on take off but I don't have a lead foot so nothing to complain about. Hwy RPMs dropped a couple of hundred but get about the same MPG as before. Offroad, haven't had a problem as when needed, 4LO is a beast.