DON... I TOO HAVE 2 CYL HEADS SAME AS YOURS. THE TOP HEAD HAS A CASTING.. W5A 601A 2-9-29. THE BOTTOM HEAD..W5A 506A 6-4-28. IS THE BOTTOM HEAD CONSIDERED THE BETTER OF THE TWO?
I would think the bottom head would be more desirable. I intend to check the volume of both heads to see if there is much of a difference.
I plan to use the bottom head on my project and will probably mill it .030" as well.
Do You own a car built by Durant? '23 Star Touring, '27 Star Coupe