Had the same issue a few months back, I have a few more mds than you do though but the combo of the 4.56's and high stall torque converter made it really hard to get off the line straight. Try moving to a wider tire, I moved from a 275 to a 305 and I had no issues today at the track hooking up. You can go with a drag radial but you need one tall enough to hold the 4.56's most are under 28" tall and with a 4.56 you really need something in the 30-31" range.

 

I dont think you are in third there, you are probably in second prime as it will hold you til 90mph or so and feels very very weak

 

i know my truck...it is third gear 0-38 1st 39-65 2nd 66-105 3rd, second prime is for downshifts

 

^he's right. 2nd prime is for downshifts, you shouldnt hit it on the way up... this is why us '03 guys have to be careful with TMR delete... leave overdrive on and downshift hard into 2nd prime... bye bye tranny

 

Doesnt 03 use the 545rfe?? If you can get rid of torque management im all ears!!

 

I did the TMR mod and didn't think it made much of a change. I had installed a SC3865 and had already modified shift points and torque management so I'm guessing the TMR mod really didn't change much. Also, I didn't know about the 2nd Prime problem and have always just nailed it to pass, allowing it to down shift to 2nd prime. It doesn't chirp downshifting, but it is diffently pulling very hard. I often do get a chirp with 2nd gear change from a standing start. I am currently running a peg leg 3:55. I would like to get a baseline time at the strip before making changes but probably will settle with data logging. The little red truck is a lot of fun.