vacuum switch

["Rolf R. Radicke" <104071.2715@CompuServe.COM>]

It is my understanding that a vacuum switch was an option on MGBs with
overdrive,   
so that if you came up to a really old loser in a big boat that you cold pull
over into the 
left lane and pass.  The vacuum would disable the overdrive until you took some
presure 
off the gas pedal.  This switch was originally fitted to 62-67 MGBs, with the
D-type O/D. 
The vacuum switch is Lucas number 34508 if that is any help.  

Kai Radicke
66 B (no overdrive and under restoration)