I'm interested in doing 4:10s but wanted to get an idea of how it would compare to 3.73's with stock tires. So with the help of the discount tire calculator (http://www.discounttire.com/dtcs/infoTireMath.dos) and a little bit of math I came up with a comparison. I figured I'd post it incase anyone else was interested.

This data is for 60 MPH, using a 42RLE with an overdrive ratio of 0.69:1...

Stock 235/70/R16 / Stock 3.73 gears
Wheel RPM: 718.48
718.48 x 3.73 x .69 = 1849.1
1849 RPM @ 60 MPH

245/75/R16 / Stock 3.73 gears
Wheel RPM : 682.64
682.64 x 3.73 x .69 = 1756.8
1757 RPM @ 60 MPH

245/75/R16 / 4.10 gears
Wheel RPM: 682.63
682.64 x 4.10 x .69 = 1931.2
1931 RPM @ 60 MPH

So it looks like 245/75/R16 with 4.10s is a really good match. It should perform slightly better than 3.73's with stock tires. But it's not so low that you're going to hurt your freeway driving. Also according to the discount tire calculator your spedo with read 5% low with the 245/75/16s versus the 235/70/16.

4.10's are the best match for the 245/75R16's that you can get to keep it similar to the stock gear ratio. You should see how much difference they make in the low and mid rpm ranges with some 245/65R17's. The RPMs are a little high on the interstate though. Especially with the 45RFE with a 0.75:1 overdrive. Went from 24 mpg to 20 mpg. Still get over 20 mpg from 45 to 60 mph. Wish I could find some way to get the transmission computer reprogrammed for the 0.67:1 2nd overdrive on the 545RFE.

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June 2001 Liberty Limited 4X4
Frankenlift II Premium, Al's Upper Arms, 245/75R16 C Silent Armors on Moabs, RL Skink Super Sliders, Rear DTT, Riddler Diff Cover, Fastman Throttle Body, Profinish-Proglass Hood, Borla Dual Outlet Exhaust, TransGo Reprogramming Kit, APS Stall Converter, 4.10 Gears, B&G Chrysler PCM, Lots of Line-X, etc...