With 4.10 gears and 37" tread, I doubt you'll be at 3100 at highway speed. Check it out and see where you end up. If you are closer to 26-2700, you'll still get much better mpg's than shifting up and down bogging down the motor.

Your only recourse is to regear to the steeper 4.56 gears, which would yield minimal yet slightly positive gains (but honestly isn't worth the expense), or come to the conclusion that 35" tires are a much better solution for a DD. A wider 35" would still look good on your rig.

And +1 on the above suggestion to ditch the spare. Hauling around the extra weight of the small spare when you can't even use the tire provides no benefit and looks the part.

 

So how did he try Flowmaster? Last I checked they didn't make an exhaust system for the Alpha. I run the GM permormance exhaust on mine. Love the sound. Strange too since in the 3 you don't notice it but when my wifes driving you hear how good it sounds when shes pulling away.
I would also suggest a Superchips programer. Works great.

 

 

For comparison sake, I ran mine in 3rd on the highway on the way home from work tonite. 31-3200 rpm's @ 65 mph...but that's with 32" tires and 4.56 gears.

With 37" tires and 4.10 gears you should be running at a much lower RPM. I'd guess closer to 2500 rpm.

 

?what? If I flatten a tire off roading I'm going to need that spare.

The only violence to be worried about is what a 5th 120 lb tire would do to the back door

 

That's what's up, thanks for the lead.

 

nah, #1 priority is rarirty. The 37s stay.

But any other advice where people have massaged hp and mpg would be great.

Ok, once again, I'm still confused by this comment. Yes the spare is stock and smaller. Literally 80% of modern cars have smaller spares.

Obviously if i rip a hole in my sidewall I'm just worried about cursing the sky then creeping back to civilization, not putting on a new 37" and continuing to sling mud. If I brought a 5th 37" the swinggate would probably snap off when I was trying to get out the jack anyways, making the day exponetially worse.... and I don't know a sole who would take a spare off and on - of any size - every 5 days.

 

Nah the reason I posted that number was because it's what I was getting cause trust me I was trying everything. 3rd, 4-wheel high lock, no TCS, blah blah blah. If it dropped it was 3100 @ 70 mph.

The best part? like half our highways in Texas are 80.

 

80% of the cars aren't AWD. You WILL cause damage if you put that on with the 37's. It sounds like you may be in a little over you head with what you have, do some research. Also, mow your grass.

 

Well then your next option is to add horsepower to that thing. I personally would supercharge that thing