Gear ratio questions

[thegasman]

Hi i have a 99 ranger xlt 4x4 or atleast the body and frame is.
The motor, trans, t-case, front and rear axles complete wiring harness,dash, center console, and seats are from a 99 explorer limited
those parts are as follows
4.0 sohc v6, 5r55e trans, bw4405 tcase, the front and rear gear sets are 410:1 all stock from a low mile doner
now the stock tires were 255/70/16 i am running 32/11.50/15 bfg mts
with the stock setup at 70 mph the truck would turn 2406+- rpm
with the 32in tires at 70 mph it should run 2206 but actually runs 2500 rpm
should i reprogram the trans? should i just go with 430 gears? or do both so that the truck thinks it has stock size tires on it

 

[disciplerocks]

32s with the 4.0 and 4.10s shouldn't give you any troubles.

 

[thegasman]

well the doner truck sat for a year with no power is there a possability that the computer needs to be reflashed? maby it lost its factory settings

 

[disciplerocks]

No. When you disconnect power for more than 5 minutes, it clears the ecu back to the factory settings. Then after it runs for awhile it adapts to your specific motor.

 

[thegasman]

then any ideas on why such a big difference in rpm

 

[Viva*the*Ranger]

I had 4.10's with 33's, on my 03 3.0 ranger, and it was perfectly fine. No worries.