The people who made the original windshield wipers (motors, et al) for our '88 sedan were Cleveland Ignition (ClevelandIgnition.com). When I dealt with them a couple of years ago, the contact was Susie, 800-362-1214. I didn't purchase a motor, just the replacement innards and it took a 3" wiper shaft (for 23 bucks). The units are type WWF (important info).
They delivered promptly and were knowledgeable and easy to work with.
Joel Albert, Potomac MD
"Charlie B" - 1988 32' FBS
Twin 318's/FWC/16x15 nibral props
docked Deale, MD