7.25 front differential gears

[4D55 Performance]

Spencer you are starting to Jerry rig my truck . Are you going the route of Kerby ? Or Eric ????? It will not have the same performance.

There are some concerns I will need to cut the radiator support to remove the front 3rd member. I don't know, maybe it will be easiest to just cut front cross member out because it is a pain to unbolt it.

I hope I have my head on straight and that's why I am asking around. Here's the data Mike. What do you think?

The performance should not be affected much. From putting a few thousand miles on the truck it is obvious it is much happier at 2400rpms than 2600rpms. I want to decrease the tire size so I can lower the torsion bars as well. It will also look much better with the original tires and wheels. Currently the torsion bars are cranked all the way up to avoid rubbing issues with the oversized tires. I really do think it is the best solution to the problem. The truck is making 200 ft lbs torque. Originally it only made 125 ft lbs or torque so I am not worried about performance.



Current Setup

Tire Diameter(inches) 28.4" 225/70r16 Michilin, These tires rub due to the backspacing. They are also on 16" aftermarket wheels.
Gear Ratio 3.909
Miles Per Hour 65mph
RPM @ 65 MPH-In Drive 3006rpm
RPM @ 65 MPH-In Overdrive 2600rpm



Purposed Setup


Tire Diameter(inches) 27.7" 215/75r15 BFG AT, This is the original tire and tire size and they will be mounted on the original wheels
Gear Ratio 3.54
Miles Per Hour 65mph
RPM @ 65 MPH-In Drive 2794rpm
RPM @ 65 MPH-In Overdrive 2414rpm