thanks to all for suggestions. now we checked spark plugs, a little white but not bad. since car rebuilt only driven 40 miles. compression test all 120 except 5 & 7 115. book said s/b 180? checked vacuum advance disconnected, no change in idle, could that be the problem making the engine run hot?. not a new distributor. right now when you drive the car temp goes up to 230 and radiator boils over. any more suggestions? thank you so much for all your help!!!!

thermostat is good. coolant level is good.

added 7 blade fan, and a schroud . radiator was checked, all good!

Sounds like you have checked just about everything. Have you checked radiator hoses? Old hoses can look good on the outside but be collapsed on the inside not allowing the coolant to flow properly. And you are sure you don't have a water pump issue? Have seen even new ones not pump properly.

I guess the obvious question would be did it run hot before the carberator was installed , and how long does it take to overheat . Does the temperature climb steady to 230 when run from cold or does it get to operating temperature , for awhile then slowly rise up to 230 from there . Did somebody install a clutch fan on the water pump. Just as a suggestion , before hearing your answers , have a reliable mechanic do a CO test at the radiator to see if that new engine has a headgasket problem or worse yet a block problem . You would be checking to see if combustion gases are entering the cooling system , there is a simple test for that using a bulb , glass and a chemical .