Don't need much to get the desired 13s with the power plant you are starting with. My 6.2 is 4x4 and heavy as hell can run low 14s with just a tune/exhaust. Just get you a cam and be done, plenty of good shops on here to get you there. Good luck and welcome aboard...
--2013 CC Z71, Edelbrock charged, cam, long tubes, 4.5" Zone, 285/70/18 KM2s on Gear Big Block, Kenwood system, LineX, Retrax, Katskinz, NFab.
--2012 Dmax CC Z71, Cognito UCAs, braces, Fox 2.0, LineX, Nfab, Retrax, Ranch Hand Front/Back, Custom Katskinz, Black Gear 18x9 wrapped in 285/70/18 Toyo MT.