04 TJ/LJ Stock 4 Ltr 6cyl. Cruise control, Stock Slush Box with overdrive, Rubi Crawler, Rough Country 4" long arm, G2 D44s front & rear geared 4:10, ProComp Extreme M/T 285/75R16 that measure @ 32" new. When I changed from 3:73 to 4:10 and 32's my speedo was right on checked with two GPS's. Thought that's cool I should be the same as stock. But in overdrive @ 65 MPH my Tach is @ 1850-1900 RPM and in Drive it's @ 2800 RPM. At 65MPH & 1900 RPM it's a dog, wont stay in overdrive on any rise in the road even a very slight long straight elevation change. And any overpass it falls on it's face and down shifts. I get out west and it will go right past drive to second and close to redline chaseing to get back to 65MPH. I drag a small trailer on dedicated trail runs 4'X6' to carry my offroad tires and steel rims, door dolly, jack & stands. I might as well be draging an anchor. The poor trany goes through fits trying to stay @ 65. I'm going to 33" drive tires with maybe a set of 35" dedicated offroad tires. Looking @ 4:56 or 4:88 gears. But I don't know how to do the math or formula to use to get an ideal of what gearing I realy should be @ to be in a power range of 2200-2400 RPM @ 65/70 MPH in overdrive on the highway . I might be wrong about that RPM range for best power MPG trade off . Not worried about offroad the Rubi Crawl takes care of the low end .
Any and all HELP would be Greatly Appreciated.
If there's a Gear Guru out there HEEEELP