72 mach 1 starter/flex plate problem

[spstang]

Can anyone please advise. I have just rebuilt a 351C and installed a new starter motor which is identical to one removed. problem is that the flex plate ring gear will not quite clear the starter bendix gear and engine will not rotate. Removed starter and fitted a washer between starter and bell housing and it is now fine. Has anyone experienced or heard of theis problem before?
PLease advise.
Thanks
steve

[fast64]

I've heard of people having to shim their starters like you did, its not a big deal.

[gasman66]

if you go to pep boys , they have a starter shim especially for fords in the "help" parts section