I have the black bear tune on my 96 k2500 7.4 vortec and opted for a soft/ mild transmission tune and sent them my performance specs with JBL shorty ceramic coated headers + duals through a magnaflow muffler and it was the cherry on top to tying all mods together. Highly recommended like the other have stated! Order online and then send back your black box for the core = no down time!