Not a c but hopping someone knows what this it. New to me.

[BJS racing]

does anyone know what this is? It's on a 78 Lil Red Express truck. Not as familiar with the newer systems.

 

[69monaco]

Found this on the net ;

1977 Dodge B200 VAN

Electrical Switch Part Number: 3874129, part number 3874129 H8D printed on case potted three terminal electrical timer/switch operates vacuum switch on carb which kicks throttle plate open.

 

[BJS racing]

Thanks a ton man!