http://www.southeastchevyparts.com/How-To-Identify-A-1955-1957-Chevy-Electric-Wiper-Motor_b_23.html
These bolt onto the fords
Put a 5047988 on the Raunch Wagon. Works great. I already had a switched relay under the hood so installation was 10 minutes. $100 on eBay for a used one.