HEI ignition modules failing

[Lobo'74]

My HEI ignition module dies about every 11 to 12 months. I called the PO on this as he had done the rebuild on the engine. He said he bought the HEI distributor from a chain auto parts store (like Advance Auto) and it had a lifetime warrenty. He just took the whole distributor out when the ignition module failed (yearly) and took the distributor back to the auto store and got a new one.

I found that he had wired the HEI to the tail lights circuit and thought that was the problem. I thought that without a "pure" 12-14 vdc source the module would burn itself out regularly (like it was doing). I rewired the HEI with heavy gauge wire to the unfused block on the stock fuse block. Truck ran great for six months then just didn't have the power it should. I pulled the plugs and found they were VERY, VERY fouled. I got rid of the Bosch platinum plugs and went to NGK plugs. Truck ran great for six months then was hard to start one day and impossible to start the next. Pulled the plugs. Fouled, but nowher near as bad as the Bosch were. Also pulled the HEI ignition module and it was bad.

I relpaced the NGK's with Autolite racing plugs and put in a "lifetime warrenty" aftermarket HEI module to replace the stock AC/Delco module that failed. Truck runs like a champ. Wanted to go out and smoke tires a little but with my sick tranny I am leaving Truck in the driveway for now.

Could the plugs fouling put more of a load on the ignition module and cause it to go bad? If so then I just keep playing with plugs until I get a set hot enough to not foul but cool enough to not allow post shut down run on or detonation, right?

If the plug fouling would not cause the ignition module to go bad what am I missing? Why do these things quit annually? Is it just to make sure I don't miss the annual anniversary of when I bought it?

Any thoughts?