So, as it sits, I have the 9.75 rear, with 3.55ls. Currently running 285's and a tuner. Truck runs good, but I hear gears make a huge difference.

Well, I have a buddy who knows how to do gears, so labor would be free, just parts for both diffs since I have a 4x4 is my cost. So I am weighing heavily on changing gears now.

So, my dilemma is I don't know if I should go 4:10, or 4:56. Reason being is I currently have 285s, but really want to lift and got 315s. Just don't know how soon I'll be doing that. So, I would hate to go 4:10, then get the lift and 35s and regret not getting the 4:56. But on the same side, I would hate to go 4:56, and wish I would of gone 4:10 b/c I changed my mind about the lift.

So, I guess my questions are: Can I run 35s on 4:10s, or would it still be sluggish, and suck down the MPGs? Or can I run 33's on 4:56s for awhile and have it not mess anything up, not lose performance, and not see a drop in MPGs? What would yall do in this situation?

 

you can run 33's on 4.56's... it would be like running 4.88's on 35's.

 

I would also go with 4.56 if you're thinking of lifting and going to a 35" tire. Living with 33" tires and 4.56 gears for a while will be much better then eventually living with 35" tires and 4.10 gears.

 

I agree, go with the 4.56 gears and do it right the first time VS having to do it again later