First my questions in case you don't want to read everything:
1. What is the scale of certain positions on the stock water gauge? Say center, top white line, top red line?

Went to the guitar shop today to drop off 2 guitars. The 7 proved again that it's only a sports car, fitting two guitars proved complicated (not really, but they were spread out in the car).

Outside temps around 110F. Intensely hot.

No problems on the way there (7 miles of interstate, 7 on the streets).

Started her up after dropping off the instuments. Temps are a couple of degrees (directionally, not temp) above center on the stock gauge (haven't finished installing the new temp gauge).

I kick on the air full blast, turn the temp **** to heat, open the windows and start driving.

The temps rose a little more before I could get to the interstate. I started to worry.

Once on the interstate, the temps rose some more over a couple of miles, topping out about 4-5 degrees (directionally speaking) short of the top white line on the stock temp gauge. I'm getting worried...

Then they start moving the right direction, down. All the way down to "normal," slightly south of the middle of the gauge. I'm not so worried...

They stayed pretty "normal" once I got on the slower streets, moving to the center of the gauge, but pretty much staying below the center. Worry fading, whiskey and coke here I come...

Now then, I recently converted to Evan's, so I wasn't really worried about running hot (scratch that, I was freaking scared, but once I thought about Evan's and how it works, I was less worried). Overheating involves coolant failure or system pressure failure resulting in the loss of coolant. My Low Coolant light never came on. The car has been cooling off for about an hour, and as usual, it doesn't drip any fluids.

This was also my first longer drive (over 10 miles) since putting in the Evan's. And the outside heat was hot (felt hotter than 110 to be honest).

I'm running the stock radiator with an aluminum AST. The system is pressurized right now, I'm about to convert to 0psi.

In the next two weeks I will be putting in a down pipe and have the rest of the temp gauge installed.

I'm not worried because
1. The coolant system didn't fail.
2. Evan's has been known to drive hot (per other forums members).
3. Evan's allows the engine to be hotter without dire consequences (coolant or coolant system failure).

Should I be worried? Should I change my thermostat?

Thanks.