I've read a lot of the discussions on here and I can see the horse trailer trend. The only trailer I pull is a 26' RV trailer and the ocassional utility trailer. I have a 99 Superduty Crewcab 7.3 PSD have an 8" lift with 38" tires. Superchips tuned, AFE stage 2 Cold air intake, 3" downtube and straight piped exhaust. Having said all that, as you can probably tell my speedo is off. Is there a programer or speedo gear to take care of this??

I haven't used any myself. Those tall tires work against max towing capacity.

Superchips and Hypertech have programmers available to recalibrate your speedometer.

Link here >>> http://www.sporttruckdirect.com/Superchips_FlashPaq_Micro_Tuners.html

Thanks Hosspuller, the link took me to a speedo calibrater that dosen't work on 7.3 or 6.0 PSD. I've seen these and thought it was just what I needed but it's for V8 and V10 gas.

Were you looking at the model 1846?

The page for that model specifically lists 7.3 and 6.0 powerstrokes.

try here >> http://www.superchips.com/products.php?pk=50&pvk=109&cm...%2BGas%2BTrucks/SUVs

Here's a link to the Hypertech products.

>>> http://hypertech.com/Products/Speedometer%20Calibrator

I see it now, the Superchips one says Gear ratio calibration not avail for 6.0 and 7.3 PSD. I'm not sure how it can be acurate if it dosen't know the gear ratio. I don't have stock gears, I'm running 3.73's. I saw the Hypertech one too looks good. I'm going to get one and I'll post how well it works. Thanks for your help bro.