Jake's post got me thinking: When we shave tires, maybe we should do the sidewalls?
Thank you for your help, Jake, Andy, and the folks who have PM'ed me.

I do have a good, big radiator. Will check t-stat.
Car runs the early model under-radiator oil cooler.
I've seen Jim's impressive book.
Making an airdam for brake cooling and radiator flow - have the Mazdacomp rotor ducts. Hawk blue fronts, black rears for now, with cockpit bias adjuster.
Car has the Carter/Holley pump/regulator setup. I run 1oz two-stroke oil per gallon of fuel, normally pump gas or 100LL avgas to avoid vapor lock (5,000' ASL and 100-plus track temps).
Running the Kia Sportage 4.77 LSD.
Front springs 400lbs/in, rears are 175 or 200 lbs/inch. Considering stiffer rears - any suggestions on sources?
What make/model tire do you like?
As a newbie, I wonder if the tri-link $$ is better spent on seat time and coaching?
Can you explain what you mean by "the hole under the thermostat" - is that where a temp sender used to be?
Do folks leave in the factory underhood proportioning valve?
What's a "good oil" - synthetic or not? What weight?
What are the "never exceed" oil and water temps, with temp senders mounted where?
Thanks for the help!