mine was made by calvin at trex tech. i got the one that keeps the heater grid and whatnot, this way you can use it on an un tuned truck and i believe it helps in cold weather areas but nobody knows
2013 gmc sierra 2500hd
SDP 3" Y bridge, 5" intake. DRP S475/stock charger kit. fleece powerflow750 4"downpipe and charge pipes. drp driver side charge pipe, drp fuel sump
5" mbrp full dp back straight exhaust, mbrp 5-6" tip, fass150 titanium. all egr system removed. pcv re route, ppe manifolds and up pipes, custom tunes by kory, efi live
fuel throttle 20x10 wheels on 35x12.5's. zone shocks, ZONE 5" lift turned down for flat cvs.
cognito PISkit. rough country tie rod sleeves,
bds ladder traction bars, removed side mouldings. home made rbp grill, home made spyder head rack