ok heres my situation, i just installed a 383 fully forged bottom end with AFR 190 Heads with bigger valves, port work and beehive springs, custom blower cam, etc.. there was no shortcuts with this build....

I fired the engine up and followed the breakin procedure for the cam...by the way this is not the first time doing head/cam swaps in the LT1 cars...the car ran perfectly except for a idling problem which i thought may be due to the bigger cam...the throttle response was unbelieveable... so i finished putting the rest of the items back on the car so i could take it out to the street for a little test run.....the car seems to have a bad missfire....i have installed new tr6 plugs, MSD opti, and OTVC wires while i was rebuilding....I pulled a spark plug to examine it and its a little black looking but not wet or fouled with fuel....the ceramic is a little carbon/sooty as well between the boot and head....on the passenger side of the engine where the alternator is mounted in front of the valve cover, it was a tight fit for routing the plug wires behind....if they were touching the alternator would this cause some of the missfire? please throw some ideas at me...I'm very desperate as i have to have this running good before the long weekend coming....Sorry for the long post that may seem like a jumbo of words but i am drove out of my mind here...

 

Check your plug wire placement and valve adj again.

 

I would check plugs and double or triple check the wire routing. Make sure everything is snug and nothing is arching.

 

Your valve adjustment can cause the same symptoms
Adjust from 0 to 1/2 turn past zero..

 

too loose or too tight?

 

Tight.