Mutt,
A quick "google" of "newport electric wiper motor" yielded a ton of information. Here's one on a '55Packard

newport packard.jpg

; the Newport site says that the '37-38 Buick model clears the cowl vent and Heater/AC - https://www.newportwipers.com/options.php ; and says that it bolts to the OEM mounting brackets. Sounds pretty easy - just send them money!!