My 2 cents is that I HATE overheating cars.

Changing the thermostat wont make it run cooler, all it will do is open earlier
Changing the radiator cap for a higher pressure one is one of the 1% / marginal changes - it helps, but doesn't solve the problem.

Had a 1987 Twin Turbo Corvette (factory turbos) that overheated:
Tried higher pressure caps, better ducting, lower temp themostats, turning on thermo fans earlier - all "helped", but none solved the problem.
I just had to look at the accelerator and it'd overheat.

It was only after I bit the bullet and pulled the radiator that I found the 2/3 of the tubes in the radiator were blocked.
Go a new one built - with and extra row and no matter how I drive it, no matter how hot it is outside it wont overheat!

With my recent Panel Van, I didn't muck about, went and got a 4 row radiator made up - never overheats now!

My advice, flush out the cooling system several times, bang in a 4 row radiator and enjoy driving it.