I have a 2000 F150 XLT with K&N FIPK, Flowmaster Exhaust, Diablo Chip, Shift Kit, and now 4.10 Ring & Pinion. My Question is this, will my speedometer have to be recalibrated? I stayed with the stock size tires (255-70R16). I've been told that the speedometer reads off the tires, and as long as I don"t change the tire size there is no need for recalibration. Any feedback or advice will be greatly appreciated. Thank you very much.

 

If you change either tire size or gear ratio your speedo will be off. The only way that it won't need to be adjusted is if the change in tire size is offset by an equal change in gear ratio.

 

Ditto's to powerstroke - gears will mess up your speedo. With that said, if you have an auto trans, you can have your Diablo reprogrammed to compensate the change.

Now for a few selfish questions - Do you like the 4.10's? How much did the swap cost? Any insights to the change?

Thanks!

 

So does that mean in my 97 if I go from 3.55 and 33's to 4.56's and 35's I won't have to get the VSS from Superlift to correct my speedometer and shift points etc? The VSS is supsoe to control shift points speedo and even air fuel from what I understand of how it works which is why Superlift makes the VSS to reissue teh proper signal to the PCM?

Richard