dumb question....
 

Since i don't do any off-roading and am in the process of lowering my truck(4/5)... should i re gear my rear end for better performance???

You could certainly go with a lower ratio if you want better low end performance

I don't think so.. just lowering it and going with an overall smaller diameter tire will give it more zip.. I speak first hand from experience. Just going to the smaller diameter tires will "regear" it.. and I don't see it neccesary to regear the rear end if you're already going to be running smaller tires...UNLESS you have like.. a 3.08 gear ratio or something like that lol in which case I'd probably go to a 3.73.

Right it does depend on the height of tire he is going to be running. But yep, shorter tires will help with the low end.

Don't really have to. With the smaller tires you don't really need them.

no.

I will be running 275/35/R18s so who knows what will happen... Was just wondering. I do some long trips in the truck but mostly just short trips around town...

youve probably got 3.73's or 3.55's....smaller tires will make you feel like you have a lower gear ratio....

forexample.....stock tires are 28" tall and stock gear ratio is 3.55:1. Then you go to 26" tires...just that change will make it feel like you have 3.73:1. Your rpms on the freeway will be higher with smaller tires....starting/acceleration in town will be "quicker". (note: just an example...i have no clue mathmatically what your new ratio would be with the new smaller tires. Twas just an example to show what i mean)