[68 TT]

Try a lower profile wiper motor like the 80's vintage S-10 truck & S-10 Blazer wiper motor. I have one on my 68 Camaro but the truck wiper motor has a different bolt pattern. You will have to mess with the mount bolt pattern & firewall seal issue and the pivot arm orientation but those are pretty easy fixes compared to relocating your PCM and under dash wiring.

It also uses a separate electric washer pump to give you even more room. I used an 88-98 truck washer jar with attached but hidden electric washer pump with this wiper motor.