This is gonna sound back asswords, but i actually had to use a lower octane gas than 93 to get my truck to start running decent again. has anyone ever heard of this? the funny thing is, it is actually running better. Also, what's average compression for these trucks(5.3's). I tested 3 cylinders, 1 from 1 side and two from the other and i got 170psi in one and 165 in the other 2. i got lazy and didnt feel like pullin out the other plugs.