1968 Mustang 302 ignition problems

I'm having some problems with my dads 68 mustang with 302. The car idles fine but when you step on the gas it only fires on about half the cylinders. It sounds like it has a camshaft like a pulling tractor. It'll peel the tires off then send you through the windshield that is if you can keep it running hknow. The car has a crane cams electronic ignition that replaces the points. I can't figure out why it's doing it. Where do i start?