Which HEADS

Needsaresto, You are right, the exhaust ports on the mag's are better than the LA heads. But the intake isn't. They are both about equal. With simple bowl and port work the LA exhaust is as good as the magnums. Well ported LA castings can easily approach 180-190 cfm range on the exhaust side. While the magnum exhaust port is better in the as cast form, it is on the 'smallish' side. 190 cfm range might be difficult to achieve. And even if you can,.. it isn't better, just more expensive. I still believe that it is less expensive to open up th LA's, than to change over to the magnum set up. Being that you already have the LA parts. JMHO. Good luck,
Terry.