All the port matching I'm doing is to the Edelbrock head's port size. Manifolds ported to this dimension will fit my 428CJ, and will also fit the Edelbrock heads when I upgrade to those. I don't have a readily available set of MR cast iron heads to test, and if I did, I'd just open the heads up to the Edelbrock port size also. So, I think I'm under control on this particular question.
Jay Brown
1968 Shelby GT 500 Convertible, all aluminum 489" 1030 HP Supercharged FE
1969 XL Convertible, 460
1969 R code Mach 1, 706 HP 511" all aluminum FE, 10.457 @ 127.47, 2005 Drag Week Winner, Naturally Aspirated Big Block
