dustiebutt

This thing is driving me nuts .....I have a GM crate L76, all the DOD stuff deleted, new GM lifters, new GM springs, new Comp cam part#54-000-11, (214/218 dur, 111 lsa, .559/.562 lift). From day one it has had a slight vibe from 1000-12000 and 1700-2700 rpm. Smooth as silk in all other areas. Shows misfires in #5 and #8 on HPT data log. I did all the logical things to try and isolate the problem, switched injectors around, switch coils around, new plug wires, vacuum leak test, checked every wire out of the pcm , installed new crank damper, pulled the pulley belt off to eliminate accessory possibilities, ran the motor with GM flex plate only, (this set up was built with Mcleod flywheel/RST street twin clutch and Tremec Magnum 6 speed). Tried several different tunes. After all of this messin around the slight vibe has not changed. I don't want to tear the motor apart but after eliminating all of the external possibilities, my thinking is I may have a bad lifter or two, maybe a bad cam or even bad springs. It is hard for me to believe that having all new parts I could have an internal problem but I know not all new parts are perfect .............Thoughts on my dilemma???? Maybe someone has had the same problem ???? Thanks in advance !!