Dustin, here is my understanding(?) of the mount types and their application, given John Mummert's reply to a similar question recently. The mount with the narrower reinforcing ribs would be original to 54-55 Trucks and 55-57 T birds. The mount with wider reinforcing ribs would have been introduced in 1956 Trucks, but should also be useable with 55-57 Tbirds even though not original and also useable in the earlier trucks, again not original. How far past 1956 the truck mount was used, dont know.
So your mount is a 1956-195? truck mount.
Mike, located in the Siskiyou mountains, Southern, OR 292 powered 1946 Ford 1/2 ton, '62 Mercury Meteor, '55 Country Squire (parting out), '64 Falcon, '54 Ford 600 tractor.
