Wouldn't it be easier to just buy am ignition switch with a key and wire it up under the dash to do your testing?

Also, I'd turn it over by hand before I tried to spin it with the starter. You'll end up breaking the piston rings, maybe bend some pushrods, etc

1950 Chevrolet 3100 (Ol' Roy)

1939 Packard Standard Eight Coupe (The Phantom) | 1956 Cadillac Coupe de Ville (The Bismarck) | 1964 Ford Galaxie 500 coupe |1966 Ford Mustang (Little Red) | 1969 Pontiac GTO (The Dishpit) I 1979 Ford F-100 | 1976 Ford F-150 (Big Red) | 1995 Ford F-150 (Newt)