4wd, really? figured that would slow you down. do you go back to 2hi at some point ?
It will slow you down a little as far mph but will net you a quicker time, unless your gonna get drag radials, and no on your truck you can shift out under a load, only the auto systems will shift out under a load but some will argue that it still won't but I know it will because I had one in my 12 and there quite a few more that have been trying it too and it's working.
2013 screw fx4 loaded 3.55 Southern Speed Inc. T4, innovative(EcoInjection), Leading Edge Tuning, Livernois 93v10d, 5* perf/tow and perf, Unleashed 93, MPT 93 race, Solo catted DP, full race resonated exhaust, afe stage 2 cai, blade runner charge pipe, BBK 73 mm throttle body, ATP intercooler, tonneau cover, recon tails, anzo 3rd brake, plasti dipped, custom ecoboost and fx4 decals.