Reground or welded up lobes with .465 inches lift at the cam lobes; and only about 20 degrees of additional duration added. Also helps correct the late intake timing that reverses the flow of the air/fuel in the induction circuit ramming it back out of the carburetor. No core trade in required. Cams are used original extremely straight cores that have been reground. bigpig41 on the hotmail serv...