lb7 vibration/misfire
 

Sorry for long story on first post. Got an 02 lb7 with 90,000 miles on clock. Engine runs like it has a misfire. Also has crankcase pressure at oil filler cap but no smoke(pulses cap up and down about 1/2 inch in hand). Compression check is 400 psi on all cylinders. Fuel rates were off on 3 cylinders so it got new injectors. Fuel rates are now in order now but still has misfire/vibration. Also pulled balancer off front of engine to check for sheer, no problem found. The longer the truck runs the worse it runs. Any help would be appreciated. At wits end.