Was the solution something you can purchase or did you fabricated it?.
I ask because I have the same issue and got rid of the wiper motor. I don't take the car out during rainy season because its not safe with the 426 stroker, no ABS, etc anyway.
In my case even without the wiper motor I found that some of the boots still rub in the firewall at times. So after a while I had some spark going into the chasis, had to tape those MSD boots to prevent that from happening. Just received the new boots, but the clearance is too small.