Originally Posted by jross

The overheating was either an obstruction in the cooling system, or the water pump failed. The engine got hot enough to melt the Viton lines while the radiator was cool enough to touch. It is entirely possible I blew the HG, which I'm hoping wasn't the case. I'd like to try and get the car running well enough to limp home in stages (it's on the road about 25 miles away) before digging into repairs like the water pump - or, heavens forefend, the headgasket.

By the way, before I go disconnecting the fuel lines, where is the primer pump on these cars? I can't find anything that looks like a primer, and that was the first thing I went hunting for. I have a spare primer of the old IP from my '83 Frankenbenz (had to fix that a few months back) that I can plumb in, but it would be handy if there's one there already for when I switch back to car's fuel tank.