Speedo thing

[Mark Prescott <cn1135@domain.elided>]

I'm trying to figure out what is in between the upper and lower 
speedometer cables in my nephews 71 scout II.  It has a circular 
appearance, has Holley written on it and has two vacuum lines attached. 
The lines aren't hooked up to anything. The only thing I've seen close 
to this is a two-speed adapter on a heavy truck that changes with a 
two-speed axle. I have no idea why one would be on the scout.  

The truck has a twin stick transfer case which pops out of gear. I can't 
locate the spring and ball pieces on the shifting mechanism which is 
supposed to hold it in gear. Any suggestions?

In the glove box is located a sticker which has Scout 810 and some 
loading info. 810?????

Later,

Mark Prescott
77SSII and lots of parts!!