THE INSIDE HAS A DIRECTIONAL FLOW FLAPPER VALVE.
NASCAR SBF FORD RADIATOR C3 HEADS -12an ALUMINUM COOLDOWN VALVE RICHARDSON #927
NASCAR SBF FORD RADIATOR C3 HEADS -12an ALUMINUM COOLDOWN VALVE RICHARDSON #434
NASCAR QUARTER MASTER 509363 SBF FORD FLYWHEEL BUTTON FOR 8 BOLT 3 DISC CLUTCHES
Fel-Pro 1262 SBF Ford Intake Manifold Gasket Set Large Rectangle Port 302 351W
SBF Ford 260-289-302 Windsor EFI Injection Port Intake Manifold Satin E42455
Speedmaster SBF Ford 351W Windsor High Rise Single Plane Intake Manifold SATIN