will this work okay?

just recently I got a 78 dodge pickup it has a newer style mid 80's 318 it has the holley 2bbl on it and im pretty sure this trk had a carter 2bbl set up on it from factory. my ? is I have a set of the small valve J heads and was wondering if they would work on this along with a factory carter 2bbl set up or would it be pointless to do so not sure what the factory compression would be? im only concerned about the smog style heads that are on it now that have those little egr holes below the exhaust ports and would the 2bbl size intake runners be to small for the openings on the heads