There is a small hose nipple on the left of the radiator cap collar that did not have a hose connected to it. Coolant was escaping from it after the engine warmed up. I couldn't find any info about it, and routed it to the overflow tank. I know that is not wher it is supposed to go but don't know the correct routing!
I now have to add a few ounces of water to the system every 100 miles or so because the overflow now goes to the tank!
I assume that the overflow from the cap (on top of the thermostat housing) that is routed to the ovflo tank is normal.

History:
Bought a rebuilt 13B last fall that my sons installed about 6 wks ago in my 87 that had sat for about 2 1/2 years! Bought alot of new parts for it including almost almost every external part.
It runs OK, except for a rough idle and the 3500ish lag. But I can live with that!However, the coolant sensor started beeping all the time. I tested it, and replaced it (by the way you can ground the lead to shut off the buzzer if you are so inclined!)

 

Overflow bottle located at the front bumper.

 

yep, overflow tank