I don't know for sure (hopefully someone will chime in that does) but I don't think they're reverse thread. Of all the motors I've done, none have been reverse thread (but that's not to say there aren't any). Have you tried the breaker bar on the frame trick? Put the breaker bar onto the frame, then TAP the starter. That usually does the trick.

Richard <img src="/forums/images/graemlins/patriot.gif" alt="" />

Had an 89 Isuzu Pickup
Had a 94 Mitsubishi Eclipse
84 Honda XL185S
Had an 89 Isuzu Trooper w/ 3.4 V6
01 Toyota Tundra SR5 V8 4Door Access Cab
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