A 6.4 with the big spartan or sct tune will run high 12s with the right driver and 4x4 launch...doesn't matter the cab configuration. A single cab should really get down. Those things are no joke.
These 6.4 guys are running high 12s in crew cabs with a tune and DPF delete with nothing else. I can't say a Duramax will do that.
These 6.4 guys are running high 12s in crew cabs with a tune and DPF delete with nothing else. I can't say a Duramax will do that.