I had a long chat with Kenny Duttweiler that has an Article in Dec Hot Rod covering a 6 liter Iron Block build up. This 2nd of 2 articles covered the MAgnuson SC so I had quite an interest.
He claims th enew heads are good for 40+ HP and he now has a GM CNC set he will test for next month. However the new heads also have a differnt intake port design requiring an intake swap as well. NA guys have a GM intake to buy bu tthe Maggie guys will need to upgrade thru Magnuson.
He also tested the 122 versus the 1900 Magnuson Blower which is worth readign about.
He used a Cam very similar the Crane he spec'ed for my engine.
Worth gettting the article and looking at these hot heads.
Last edited by dmurf; 11/19/07 05:17 PM.