I recently obtained a '91 Carat that I know needs work.
I have done coolant pressure tests hot and cold at 14 psi and the pressure leaks off very slowly, about 3 psi in 1/2 hour and I have found one or 2 very minor hose leaks which I have taken care of.  I do see evidence of the head gaskets having been done.
It has the wrong (green) antifreeze so I want to flush it and replace with the blue.

1   What is the best way to do this without removing the pushrod covers to access the head drain bolts ?
2   Where can I insert a Prestone Tee ?
3   What is the best thermostat to use? 80 or 87 degrees? I live in a hot climate SC ?

Thanks for your help,
Steve Cotsford