<VV> Choke Thermostats

[Western Canada CORSA]

I was putting the lower shrouding back on the RS today.  One of the choke
thermostats wasn't working so I decided to replace that as well before
buttoning things up.  I had a spare head lying around, I pulled the
thermostat off of it, and noticed there was a difference between the two
designs.  Other than the length of the rod going up through the head, is
there a fundamental difference between the two in the way they operate?
 
Regards,
Joel