Gear Vendors overdrive

I think I could benefit greatly from a GV OD in my '02 Cummins 2500 quad cab long bed. when going up a steep grade, the 3 to 4 shift really sucks *** and lugs the truck down. same for when the TC lockup occurs. I think it would be really beneficial to be able to split the 2-3 and 3-4 gears esp. while towing...I think Del has one, doesn't he? (67dart273)