We have a 1978 f-800 fire truck with a 477, it has a set of outlets and a rail on both sides that goes to what we think is an ERG system. Qestion is can we pulg the rusted off ports up without causing damage to the engine?
Kinda late on this one but what you are talking about sounds like the air injection system and if it is you can plug them off if they are leaking. The ERG system will go to the intake if these beasts even have one.
Napa may be able to help on that one. They should be able to look it upand tell you and can possibly get replacements. I was able to get a distributor for my 1963 534 (though i never needed it as i convereted the old one to electronic).