I'll need a 1" open end wrench to get it, which I don't have
Hmmmmmm- - - - - -I don't remember a Chevy starter having an attaching bolt or nut with that wrench size- - - -they're usually attached with a 1/2" diameter bolt or stud with 3/4" wrench flats. Better recheck that size before you buy a wrench.
Jerry