This is a Skunk2 factory replacement 3.5L Plenum part for the Ultra Race Side-Feed B & D Series Intake Manifolds; 307-05-9000, 307-05-9200, 307-05-9050.   
 
FEATURES:
• Removable Plenum in Silver 907-05-0060 or Black 907-05-0065
• 3.5L Plenum Volume
• 90mm Throttle Body Flange - Std. 5.0L Ford Pattern
• US Patent: D673977
 

Optional Billet Aluminum Plenum Spacers Available in 1L or 2L Sizes:
 
• 907-05-9001 Ultra Race Plenum Spacer - 1L Silver

• 907-05-9051 Ultra Race Plenum Spacer - 1L Black

• 907-05-9002 Ultra Race Plenum Spacer - 2L Silver

• 907-05-9052 Ultra Race Plenum Spacer - 2L Black