I have a 57 B cast iron intake for Holley carb which was ported with carb base of intake opened by John Mummert.
This done before the Blue Thunder intakes were available by John. The iron intake work is very similiar to the Blue Thunder intake.
Price $250.00 plus shipping Ted Eaton currently has the intake in his shop in Texas
You might call John Mummert for details on the intake porting work if interested.
Thanks