If you decide to go magnum, better do a leakdown test on it first. Do a quick search on "cracked magnum heads" and youll see. Also, the earlier 308 heads are equally as bad about cracking too.
True of all the induction hardened heads, so pretty much mid seventies on. Most of the run down the road just fine. And if you get heads without hardened seats, you have to have hardened seats installed. Always a trade off.
360's didn't start getting roller cams until '89, same with the 308 heads. Before that they're all about the same unless you're talking about the first few years, which supposedly have better castings.
