maximum engine temp

generally, the hotter the better, in terms of milage, emmissions, and power. But, an old V8 isnt designed to take advantage of that. With aluminum heads, I want to see a minimum of 190°. Any less, and things like valve lash and gasket load can fluctuate, and weird things can happen. They dont always, but they can. Iron, if you want to run it at 160, go for it. You may run into fuel issues and foul plugs, but if that's what makes you happy...lol. In your case, you have a T stat opening at 160...but it runs at 210 at speed. IMO, your cooling system is not optimized, and can just barely do the job. My guess is, a typical small V8 2 or 3 core brass radiator? If you have a cowl seal, try removing it. Also, block off any extra holes in the from radiator support. Use a fan shoroud if you dont have one. It makes the fan more effective, and can help smooth the flow thru the fins while you're cranking down the highway too. Todays rebuilt engines generate more heat (higher hp=more heat generated) and the blocks get thinner, aluminum heads are used, and more heat is forced into the water than what used to be. The brass radiators can only get rid of so much heat before they are "not enough..."