Running too hot

I have a 1973 ,429 Lincoln engine in a cobra kit car. Engine has been rebuilt. Can't keep it from over heating. Tried new thermostat,new water pump, after market radiater with mounted electric fan and shroud, even added two pusher fans. Was told to check timing, I adjusted timing and that did help but still runs 200-220 just cruising. If I run it any harder it will over flow the overflow tank. Was also told sometimes rebuilt engine might run hot until broke in . Have less than 150 miles on engine. I am stumped.

Forgot to add, car is also lacking in power, it's doggy.

Have you confirmed the engine is actually running hot versus just a sensor that is either not reading correctly or sitting in a pocket of air? If you're confident that all the air is out of the system and the coolant is actually running hot, and since you mention the engine is also lacking power, I'd be inclined to think your carburetor is not tuned correctly and you're running either too lean or too rich.

-Rod

Have you confirmed the engine is actually running hot versus just a sensor that is either not reading correctly or sitting in a pocket of air? If you're confident that all the air is out of the system and the coolant is actually running hot, and since you mention the engine is also lacking power, I'd be inclined to think your carburetor is not tuned correctly and you're running either too lean or too rich.

-Rod. Agreed, assuming your power expectations are reasonable, I would research the proper advance curve and base timing for that engine, get it right to eliminate that possibility. To add, an engine built with exceptionally tight clearances can run hotter during break in. Lotta possibilities here.