I have a 1992 f-150 with the 5.0 it has a jasper rebuild engine with only around 70k on it, paid 300 bucks for the entire truck but ive been getting a check engine light when I get on it heavy, could this be simply a misfire or could it be more deep, i am about to put ford racing wires, motorcraft platinum plugs, MSD cap and rotor, and an MSD Blaster ignition coil on it hoping this will help, any feedback appreciated

 

Wires and plugs never hurt but a coil other than oem can cause lots of problems. Spend that money on a Ford specific obd1 innova tester, only about $35. Tester comes with a book that has code definitions also, it's a good value if you'll be keeping the truck.

 

What mind of harm could the aftermarket coil cause?

 

The ignition system won't use the higher voltage for one and it might cause failure of other components. You're trying to eliminate misfire problems and stand a good chance of adding to them.