STOCK 318 roller cam vs non roller LA

I picked up a 88 TBI 318 today for the #302 heads, and tearing it apart it is a factory roller 318. The plan was to use the heads on an earlier 77 318 (that is already rebuilt). Is there any real advantage to using a roller motor vs a flat tappet hydraulic cam? Fuel milage, performance etc? This engine will be for my stock DD 87 ramcharger, that still sports factory 2bbl and manifolds. I would consider rebuilding the tbi motor and using it for the Ramcharger if it has a clear advantage than the older motor i have for it.
Thanks, Paul