Best coolant for our 60-70's Mopars?

My comment wasn't in response to any particular post, but I don't see how it would confuse anyone.

I don't run at any track. Purely a street car and highway/off-highway trucks.

Tried PG, it was available in KA under the "Sierra" brand name. Did not work as well as EG - even when mixed according to their instructions, gave up on it.

The combo of green ethylene glycol 50/50 with distilled water and a 180°-190°F thermostat is well proven to me. See no need to change.

EDIT: Something that I've not yet seen mentioned is the radiator cap. One of my trucks starts to run warm every 1.5 to 2 years. Replacing the cap restores normal behavior. I usually end up servicing the system at the same time.