MSD -vs- Jacobs

tried to have an msd box in a truck I had years ago. bought it brand new, wired it per instructions, was fried. msd replaced it, truck ran for an hour or so, dead in the water again. 3rd box, died after 100 miles or so. pulled the thing and and ran the factory ignition for with no troubles for 7 years...but it was a long time ago, would be willing to try them again....