65 Barracuda, 225 vs 170 motor mounts.

You are dealing with a aftermarket Part Manual srew up. The correct "Insulators" (mounts), for either the 170 or 225 slant six in a 63-66 "A" Body are the A2203 and A2204.
The mounts you recieved (A2265, A2264) are for a 67-72 "A" body (plus other applications). This is a common problem with the part catalogs. The catalogs are correct for a Dodge Dart, but incorrect for a Valiant/Barracuda. I gave up years ago, telling the parts suppliers the catalogs are wrong.