1939 Chevy Master Deluxe 216 overheating

Need help to fix my overheating on my 216. Bought and Install 1938 truck 216 that was rebuilt, and I rebuilt the water pump installed engine and overheated, coolant out tailpipe. Pulled head, had welded and reinstalled. Overheated again at same driving distance 3 miles, pushes coolant out over flow. Brought high efficiency radiator and the 5th thermostat 160/180 degree and bought a rebuilt water pump. Overheated again, not as bad, just over 220 degree. installed 180 degree thermostat and overheated 200 degree. Check OEM temp gauge with temp gun, both read the same. Installed 14 inch electric fan to lower part of radiator as a pusher (run fan with key on) run OEM cooling fan and 180 stat, drove and runs at 200 and 220 at idle. The rebuilt water pump impeller fins that run next to engine block are 1/8 shorter than OEM fin, but the rebuilt impeller I used is the same as the rebuilt I bought. Is this the problem that the pump doesn't pulling enough water OUT of the block? HELP

I'll begin by offering you this wiki article from the crankshaft coalition. Many experienced rodders have contributed to this subject, so please read through and see if you can find something in the article that addresses your problem....
http://www.crankshaftcoalition.com/w...cooling_system

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Sounds like you haven't put many miles on this engine(about 12?) Could be engine is tight , could be water pump, When its running with the cap off can you see coolant flowing?? Your timing could be off and it would run hot. As Tech said do some reading and lots of checking. Good Luck