96 geo tracker 5spd 4wd 16 valve 225/75R15, i am running 3500 to 3600 at 65 mph does this sound right and how muck better will this get [if any] when i get my 31s on here? also in stock trim will this truck turn 33s on the highway?

33s and stock trim, no.
I ran 235 75 15s for years, loved the size, 31s will be a stretch
might want to stop at 30" tires without a lift

My 89 w an auto ran 4000 rpm at 70, your RPM sounds right,
BTW the 235 tires corrected my speedo to 100% accuracy,
don't know if 5 speed models would benefit from this, check
ur speed with a radar or GPS to see if your speedo is reading
the correct speed

Wild

With a lift and a little trimming 33" will roll just fine. You will notise the loss of power though.

yep, they like being driven ay 3600-4000 rpm.

Sounds weird, but that's how they make them in the land of the rising sun...

i have 31 10.50s on mine with no lift and they dont clear worth shit. The 31s work well on the road but power suffers. I think 33s would kill the power on the road ats might work but my 31s are all im willing to live with driving it around on road and they are ats not the super swampers which i THINK are heavier

I had 31's on mine with only 2" lift, it was great for the road - I actually liked driving it more then. They're mounted on 7" wide rims. I had to trim the inner fenders a bit.
Mine is a 5 speed so the power loss is compensated by the ability to shift at higher rpm, and downshifting when you need to, but it's really not that bad. I was worried too until I just went & did it, then I wanted bigger

the five speed helps on road. you need some lift to run 31s with little problems. i have major binding problems. i think u need at least 4 inches to WHEEL 31s might have to have 5 inches I'm gonna lift mine so ill let u know at a later date driving can be done with no lift and some trimming or a 2 inch lift

i am running 31x9.5x15 tsl radials. heavy tire power is shady in 5th other that that they are awesome. 4.5 rro lift. also running cam header and hi flow intake. wheels excellent 

the five speed helps on road. you need some lift to run 31s with little problems. i have major binding problems. i think u need at least 4 inches to WHEEL 31s might have to have 5 inches I'm gonna lift mine so ill let u know at a later date driving can be done with no lift and some trimming or a 2 inch lift

You seem to have answered your question/own problem.

I sidekick/tracker will never clear 31's stock... unless you do a virtual lift, then I have seen 33's cleared no lift. Looked pretty good too.
Considering a 4cyl under 100hp motor will NEVER have much power, I dont see the major issue of losing a whole lot. 33's is REALLY making it almost impossible to maintain highway speeds/hills however. 31's + 8V motor + lacking rings/valve seals and she still could hold highway speeds even though she was slow getting there unless I had it to the floor all the time with the 5spd.

Bryce

I can't see a tracker with stock trim running 31" but I am sure someone has tried it, I am running a 93 Tracker with 6" lift and 31" Tires on 4" backspacing and 8" rim. On the road it has no problems with clearences but when I am off roading they will rub if I got the wheels turned and I bottom out the suspension. Running 31" has killed the power of my stock 8V engine on the hwy, If I am in any type of head wind I am in 4th gear wide out and getting around 85-90 km/h, I think thats 50-55 miles/h. Oh yeah I live in the praires so the land is flat. I am in the process of fixing the power issue. In a nut shell, I would not recomend 31" in stock trim. Just my $.02

i have an 89 kicker with 31X10.50 tires on stock rims.  i dont know for sure but i wouldnt think they would clear without a lift.  i went with a 2.5 body lift and coil spacers.  the only time my tires rub is when im out wheelin and turn the wheels all the way to the left.     as for the power issue,  mine was always really gutless and i didnt notice much diffrence when i put the 31's under it.    as for the rpm's,  with stock tires mine ran  4000rpms  |removethispart|@70mph   i have not had it on the freeway since i put the 31's on.

I was bored so I went ahead and put the 89-94 5 speed on a transmission calculator. 

http://www.solemnwarning.net/transmission/?id=23

This is the stock setup, you can change your tire size at the bottom to see how it affects your RPM ranges.