I've got a 1990 f250 with a 460, recently I've noticed that I've lost some power, having trouble climbing hills etc. yesterday it seems as though the headers got so hot on passenger side that it started to melt my wheel well and actually caught what I think is an oil evap line on fire, stopped when I smelled burning n ripped the flaming hose out. My first thought is a misfire on that header primary causing the heat? Would new plugs and wires solve this? Any help would be appreciated