1988 f-250 supercab 351w h.o. engines misses exhaust will burn your eyes and after a few minutes exhaust pipe after left manifold will glowcherry red. now truck has no cat at the moment carb has been redone figured it was timing chain ripped eveything down and timing marks line up perfect and rotor is at number one. thinking possible hung or burnt valve i dont want to keep guessing anyone have any ideas? feel free to email @ bobeblitz@aol.com subject f-250