There are several differences between a Denali and a Tahoe other than just the engine. Would need the full 6.2 exhaust which is larger diameter. The trans is the 6L90 where the Tahoe is a 6L80, both 6 speed automatics but the L90 is beefier. Different transfer case, I'm told the reason the Denali 6.2 is full time AWD is that the rear axle can't take all the torque all the time, so the AWD will redistribute the torque to both axles (from a GM engineer). I'm sure the 6.2 will bolt up to the L80 and everything will work fine with correct exhaust and EDU to match, just be wary of the extra torque on the Tahoe drive train for long term durability.