78 El Dorado Engine

can anyone tell me what type of engine a 78 Caddie would have in it. Would that be cast aluminum or the iron type? I have a 74 Eldo that I'm thinking of redoing some body rust not much and front bumper and grill was hit, it has 6k + miles and wondering if it is worth it or should I sell it I have no idea what that would cost as I don't have the skill for repairs and would have to pay to have it done.

A '78 Eldorado had the 425 nickel/iron block engine.
As for the '74 Eldorado, it would cost a lot to restore, and it's not a very rare car, so you wouldn't get your money back.