truck broke down towd by a ford!!

[special70gmc]

i know this belongs in the engine/drivetrain but itll get me attention here, i was driving to school yesterday at about 2000rpm and the engine just cut out my tack started jumping and very small backfires out the exaust. so i pull over ans check for spark it seems to have medioker spark from the coil and plugs but not good enouf for the msd i dont think. its has fuel and the pump works what went wrong i cant figure it out. my boss things the mag picups in the dizzy whent bad but im not sure. i also thought maybe i broke my timeing chain but the valves all move too. last thing i went and tried to start it this morning and the thing cranked fired and made the LOUDEST! backfire out the pipes i ever heard in my life dam thing sounded like 5 shotguns im stumped.

specs on the ignition are msd probillit dizzy blaster 2 coil msd 6al box and msd 9mil wires i hope you guys have some ideas and also sme pics of it being towd by a ford thanks -kyle