At an auction I bought a box with three electric wiper motors. It was marked 55-59 chevy truck. From looking at the parts vendors sites it appears that 55-57 is different from 58-59 but these all look the same to me. Is there a way to tell them apart? Thanks.

Jeff


'64 swb stepside (gone)
'57 1 ton
'53 phone truck
'59 swb
'46 1 1/2 ton
'68 swb gmc