Someone mentioned in one of the replies above that there wasn't a 318 4-bbl....but there were in the cop cars and other govt issue stuff. My buddy had an ex-cop Diplomat, and it had roller lifters, rockers and a 4-bbl.
The 4 barrell 318's with roller lifters never came out until the mid to late 80's. Military issue might have had a 318 4 barrell but I really don't think they had roller lifters until 85 or 86.
My uncle bought a 84 Ramcharger new and it did have a 318 4 barrell (quadrajet) but didn't have roller lifters.
Either way about it that's a good find you got there.