Me and my son just a 1993 lt1 lt4 heads 383 cc306 roller can comp.special grind.90 mm.throttle 30 lbs injectors. Roller rockers have .99 .44 on them adjusted them cylinders fisrts were at about 180 I got them to 220 .car is running great.but were having 0 2s burning out.running fat.why?