I will soon be installing a new thermostat in my 292. Recent posts on this subject ha given rise to confusion on my part. Should I install a 170 degree NAPA #6, a 180 degree one or perhaps even a 160 degree unit. The NAPA units are supposed to have a larger orifice. Some say use a Robertshaw while others say they are junk and go with Stant (others claim that the Mr Gasket thermostat is junk as well). I have a C2AZ-8575-A from Mac's that lists as a 180 degree unit. Another supplier lists it as a 160 degree unit. The C2AZ-8575-A cross references as a Stant 13478. Does this mean that the C2AZ is in fact a Stant 13478 or that it is simply a suitable replacement.
I read where Ted and others recommend a ristrictor with a 3/16 orifice in the bypass tube. Can this modification be made in isolation or do I understand that a hole (s) must be drilled in the thermostat? Does this (these) modifications require a specific thermostat?

In the past if I needed a thermostat I took the one the Parts guy gave me and if the rad didn't boil over I was good to go. Now I'm paralyzed by all this information.

Mark

1956 Mercury M100
1955 Ford Fairlane Club Sedan
Delta, British Columbia