I wasn't expecting to see this thermostat! What gives?

The heater pipe can just be pulled out (the barb won’t survive).  You can get another press in barb, or tap it for a brass one. 

I’ll let others comment on the thermostat. But if it was running fine, why change from a $5 stat to something hard to find and expensive?  You have to get the restricted plate too. 

Thanks Rocky.  I'll pull this barb out and figure out a replacement later...

As far as the thermostat is concerned, I did some digging and found a few applicable threads:

https://pantera.infopop.cc/top...this-argument-please

https://pantera.infopop.cc/topic/351c-thermostats-1

https://pantera.infopop.cc/top...ter-pump-by-pass-cct

https://pantera.infopop.cc/top...ifacation#6880012344

I'll have to check my water pump tonight to see if has the bypass hole or not.

a constant heater core flow path is also a bypass circuit,

it will eliminate pump dead-heading with a closed T-stat

Hi 4V,

Thanks for the reply.

I've got shutoff valves installed on my heater hoses, so during the summer no 'bypassing' is happening thru the heater core....

Update:  I pulled out the solid restrictor plate and installed one of Tim Meyer's solid brass bypass plates in its place:

https://www.tmeyerinc.com/prod...estrictor-cleveland/

The 333-195 and 333-180 thermostats are readily available again (for now), so I decided to revert back to the original scheme.  To round out the cooling system updates, I will be installing the FlowKooler #1648 water pump, and possibly updating to George P's self-bleeding header tank modification.

i see 333 series stats on Rockauto for under $5 all the time

there's also a FailSafe style that will fail open rather than closed

FWIW i believe you can remove the hat from the sensor of a 333 series stat and swap it over to a 330 series to create a custom temp 333 that might not be available