Here's the tune on my 99 5.3 truck with stock intake and exhaust manifolds. Notice VE table over 100% after tuning with an LC-1. Are the original injectors so weak that they can't keep up with this flat cam? (stock) I have 2.5" pipes off the manifolds into a 3.5" collector and then 3" to the bumper. No cats. I quite sure the filter is good because my fuel pressure was steady at 58psi