Eddy Air Gaps, Chevy/Ford/Mopar SBs

Anyone know why Edelbrock mills the center divider down about 3/8" on Chevy/Ford Air Gaps?
Mopar SB center is not cut down.

http://www.summitracing.com/parts/edl-7501/overview/
http://www.summitracing.com/parts/edl-7521/overview/