J heads $200, snag them with the quickness? FEEDBACK PLZ!

i was at the local yard talking to the owner who is supposed to be the local mopar guy, and he said he had a set of J heads i could get for $200. he also offered me $200 for my old buick that needs a transmission. should i grab these heads while i can? i mentioned id have to have them shaved down to reduce combustion chamber size, and he was like "i dont know, you got me there.." (some mopar fan :-P ) but i was thinking about offering him the car for the heads and a 4 bbl intake manifold for my car..

FEEDBACK PLZ!!