I have a dead cylinder on cylinder # 6 , new leads, new distributor cap, new spark plugs, all other cylinders working fine, headers exhaust on that cylinder is cold. Checked for spark against block and seems fine, no stuck valve as both compress as normal? any ideas I have a slight header leak on that side? don't think it's that, also when revving the motor I have a little blowback from the headers on that side along with small clicking noise (checked the rocker arms they seem fine.

Thank...

351 W Number 6 cylinder not firing