I've heard some stories of MSD's crapping out early. Not built like they used to be. Mines been good for 2 years, but I've only put 10K on it in two years.
Are yo uusing the factory ignition module to trigger it or are you wired directly to the dist. If direct, try disconecting the purple and green wires from the dist and touch/release the white wire from the MSD module to ground and see of you get a spark. This will rule out the MSD module. If you have 12 volts to the MSD on the batt wires, 12 volts on the smaller red, you should get a spark when you remove the white wire from ground.
If you're still using the factory igntion module to trigger the MSD, rewire it so you don't, hook the MSD directly to the dist, eliminates one link in the chain. Keep it simple.
Honey?? What happened to the savings account? You bought a Jeep what??
86 Grand Wag Stock with Bulltear HEI