Originally Posted by DA BIG ONE
Art, I'm thinking closer to 45mph for od/lockup w/4.10's. I also think using cruse control locks converter too.
Tire width does effect milage, but tread pattern plays bigger role the MT/R's I used made mpg suffer, the SilentArmor is more road friendly and quieter so not as bad.
Your vss is on the t-case along w/2 other speed sensors, 1 for the front drive shaft, 1 for the rear driveshaft. I just discovered the "vss" hack works a little while ago.
Hacking the speed signal from the vss to the vssb will correct the speedo only and leave the 3.73 shift/lockpoints you have now.
Hacking the vssb you modify speedo, shift/lockup to higher mph setting, abs, cruse control. TheDieselPage sells the book showing the hack of VSSB.
I used a commercial VSS re-calibrator to modify vss signal only.
Getting accurate on speedo calibration comes w/hack either way, especially if you measure tire diameter and use this measurement in re-cal.