I'm wondering about putting a TBS in my truck, F150, 5.4 liter engine, but I'm wondering if it will even make much of a difference? if so, what will it effect? MPG? Horsepower? Torque? thanks!

 

It won't do anything. Think about it, the injectors are way down near the intake valves in the heads, then there are 15-20" long runners and a plenum between the heads and the throttlebody. There is no fuel in these runners just air, so what could adding another 1/2" to this total distance possibly accomplish?