to see if the pump is pumping, how about a section of clear 5/8" hose to bypass the heater core and there would be flow there even with stat closed (and radiator/piping plugged)
is there a thought some one could have dropped a small ball in the pressure (swirl) tank and it is now lodged in the tubes?
PANTERA INTERNATIONAL
A DE TOMASO CAR CLUB
Presents the De Tomaso Forums
The On-Line Meeting Place for De Tomaso Owners and Enthusiasts From Around the World
Clicking on the banner will take you to the sponsor's website.