Chim I think I know what your getting at.
The tundra is a 4 cam, 32 valve engine.
While I can't speak for your V8, all 4 banger and 6 banger engine with 4 valves a chamber, NEED backpressure, or you will lose tremendous low end power.
Now keep in mind, this low end power you lose, you will gain it at top end.
Gas mileage WILL suffer with lose of backpressure for reasons I shouldn't have to explain.
With the 4 and 6 cylinder engines I know this to be fact with experience.
Its my opinion that your V8 wouldn't act any different then the 4 or 6.
Unless someone chimes in with a different experience, I think you should listen to me.