i could see 13.4 idk like i said depends on the tune, and how well it reacts to the LT's. i think u could go low 13's easily with the right combo. i wouldnt be suprised to see low 12's in that truck soon, depending on what ur future plans are. u got a terrific base to build on, just make informed decisions and ull be alright. i love ur truck BTW, if i was gonna get a new one id go 5.3 RCSB for sure.