Overheating new 360 help

Well so here is my story continuation. Pulled truck out last weekend and didn't push it in till Thursday. Didn't drain the water from the right side of the engine so ended up pushing 2 right side freeze plugs out and the rear right side. So out came the tranny. Buttoned the tranny up after installing new freeze plugs. Swapped to factory electronic distributor. Set timing at 16 degrees before top dead. Started cranking. No spark. Found pick up coil in brand new reman was open. Pulled dizzy again and traded pick ups with a big block dizzy and reinstalled. Started engine and had 38 degrees advance with no vacuum advance at 2500. Ran good for about 20 min then overheated again. Shut down and cooled. Since cam brake in time was done after this 20 min and the last time, started her back up and was trying to adjust timing to vacuum gauge. Turned out the edlebrock on top started leaking gas from the throttle shafts on both sides. So there's another issue that needs addressed. Go to start the truck up again after sitting for awhile and starter failed, just clicks. Would have been nice to have failed when the header was already off today. Had to push it outside (with 50/50 coolant this time) with the skid steer. Gonna be another week before I can order a mini starter and carb rebuild kit. Any ideas on the over heating? When filling it is very slow to drain down in the radiator. Checked both upper and lower hoses for a rag or something blocking it. Thermostat is new but sat in the engine for a year. Fan seams to be spinning fast enough when warm. Radiator is new last week from Napa.

I'm about getting fed up and just go back to diesels.