How do you know if its a mechanical secondary?

[us74k5]

I need to grab an old mechanical secondary 4 barrel holly carb. When I am looking for one, what is the dead give away? Or do any of you have one laying around you want to get rid of? Thanks
-matt

 

[4X4HIGH]

I need to grab an old mechanical secondary 4 barrel holly carb. When I am looking for one, what is the dead give away? Or do any of you have one laying around you want to get rid of? Thanks
-matt

Mechanical secondaries have a linkage connecting the primary and secondary throttle shafts rather than a vacuum pod on the passenger side. If you can open the primaries fully and the secondaries open as well (usually around half throttle) then it's a mechanical secondary carb.

 

[us74k5]

sweet, thanks:-)