Aluminum heads and 63 vs 65cc chambers

Dohc Rocks said
Are the 65cc combustion chambers on Speedmaster and Promaxx heads closed or open like on the Edelbrock 340 head?
If they're both closed, is there any difference in the chamber design or is it more of a case of clever marketing of casting variations?
Click to expand...
ProMaxx purchases bare Speedmaster heads and works on them here in the U.S. in Alabama.

Addressed @

103 Rainbow Industrial Blvd
Rainbow City, AL, 35906

Below is the first few lines in there about us page;

We are a family owned business that began in 2012 by purchasing the remnants of Patriot Performance and Alabama Cylinder Head Exchange.
Click to expand...

Click here for the page; About Us - PROMAXX Performance Products