Well, somebody's been into it- as
@4spdragtop said, it's got 2 bbl. valve covers and a 4 bbl. manifold, so there's no outward sign of what truly lies inside. If it's really a 4 bbl. engine, then it's a '67 at the latest, a '65 at the earliest. If the 4 spd. has an output flange, it's a '65, if it's a slip yoke it's a '66-67. That's only if it was all born together. The motor mounts and brackets are early A, so '65 or '66, depending on the trans.
Oh, check the distributor- if it is dual points then it most likely is a 4 bbl. motor- single points most likely a 2 bbl. motor with a manifold swap. I *think* that looks like a dual point, but hard for me to tell.
