4.9l. E-150 van overheating

Van 1988 e-150 4.9l. Have had a heating problem during 100 deg. Temps. For the last two years. Had a new water pump, thermostat (160 deg, ) and new radiator. At idle it will stay at 160 deg, but if I drive at all the temp will rise to over 200 deg. Or if at idle and turn on the a/c the temp will rise slowly (10 min.) To over 200. When I turn it off it boils and sends antifreese into the reserve and sometimes overflows. The van has 185,000 miles with orig. Cat. It has low power at exceleration. It sometime is hard to start and acts like the timing is to soon and it momentary stops the starter and then spins again some times hesitating 3 or 4 times before starting. Brand new battery. No loss or rise of oil level or fluids.