on mopars....there are 318 heads...which all have the same port size...
and there is 340/360 heads which all have the same port size...there is no 2v vs 4v ports...
the 318 head have small valves ...combustion chambers and ports...the 340/360 come with larger ports, chambers and valves...
to use a 4 barrel carb...you need a 4 barrel carb and intake manifold....
a intake made for a 340/360 will have larger ports then your 318 heads...but they will work.....or find a 4 barrel intake that is more designed for a 318 head...sort like a eddy performer intake...
the oil pump has a regulator spring build into it....
as far as bushed rockers...what kind of cam are you using?