need opinions on my goal for my rig

1987 cherokee- 5spd nv4500 trans-87 corvette sb 350 (stock internals)-currie axles (d60/d44) 355gears- cone filter- catco cat- vx muffler- 2.5 exhaust- 6inch tomken lift- 31inch tires- msd ign- accel dist and wires- aftermarket headers-

I might of missed a few. Anyways my goal with my rig is my dd, drag race rarely, easy to medium offroad trails, tow a enclosed motorcycle trailer.

First off i dont want huge tires, i dont know if i want all that parasitic loss of 35's. Um unsure if i wana stick with 31's or 33's. What do u think?

My gearing right now with 31's in 5th gear at 60mph is 1900rpm. I have to run gears out to 3 gran then shift then it drops to 1900rpm which is a tad doggy. what gearing? i get 15mpg to 17mpg at the moment. I wanna keep fuel economy.

I plan on adding edelbrock cam and intake manifold to bump it up around 300hp or so. Dont know if that will effect my fuel economy or not?

Thanks

6" lift and 31" tires? Really?

With 31s you want 4.10 to get to stock, 4.56 is going to be a pretty hot gear ratio. You could step to 4.56 and 32x11.50 for good float and still be a little "hotter" than stock on acceleration. Then again, with a SB350, hard to say what the ticket would be. at www.4lo.com there are RPM calculators for tire sizes, trans ratios and diff gears. I think you want your 70 MPH to be around 2400 RPM - basing this off my thinking that your peak torque is around 3800. Generally, you want highway cruising to be nearish your peak torque but not spinning it too hard. This is a compromise between best efficiency (at peak torque) and not trashing the engine by spinning it too hard all the time. Play with the calculators a bit and remember that when you go up a gear ratio you are letting the engine spin faster (more power) AND giving better mechanical advantage. So a jump to 4.10 is goign to feel kind of dramatic, or should anyway...

Your 6" lift is pretty damn tall for the tires you run - people put 35s under a 6".. might consider dropping to 4" for aerodynamic & stability reasons.

I'm going to hope / assume that you have front & rear discs with a dual diaphragm booster to stop this beast... Sounds like a bad assed rig. Pics?
Hope this helps...

Wouldnt an 87 vette engine be TPI? or are you carb'ing it?

Um just thinking i seen a ls2 wrangler on youtube run a 15.4 with 37's. Imagine what he could run if he had 33's or 31's. Or do i have the wrong idea? if u have more rotating mass even if u have the best gear ratio for them tires you still will loss fuel economy and acceleration and more stress on ur driveline parts. It would be sweet to roll on 37's but is it worth it for dd and acceleration?

37's on a dd? No way. Then you're talking about axles, shafts, joints, more lift, huge brakes, and a total loss of anything economical.

okay, how bout 33's would even out my 6inch lift. I could do it all with them and not push my currie axles to death.

33's arent even a threat to your 44/60 combo... dont listen to people who wont read your entire post...

are you loaded?

my DD is a YJ with a 350...bone stock, with 36s and 4:88s i can still embarrass ricers all day long, and comfortably cruise 80 down the highway.

id go for 35s probably.

no um not loaded. I know they can handle 37's. I just wondered what the best combo between acceleration and not having ridiculous tires and runs like a dog. Wanna keep the ricers off my back and still keep economy and more acceleration then what i have at the moment.