What is this stuff in my block?

Well the last flush with commerical flush came out with a bit of rust coloration but at least it is a transparent rusty color for at least 4" deep in the catch pan; not as cloudy. So the stuff is working out. Had to button up everything to be able to move the car and get the 16' enclosed trailer hooked to the Ram for this coming weeks work in KY. So some clean water flushes and new pump, hoses, antifreeze in the car, for now, and I'll drive it some more to see if it keeps working out.

The car comes up to temp more quickly now (partly due to the old t-stat that did not fully close) and when it gets to temp, the gauge does not wander up and down very much now, like it did before. So, much better. Never saw anything this level of gunkiness; not wonder the reasonably green A/F in the system when we got the car turned brown in <100 miles of driving. But all in a day's work, I suppose for a 52 year old buggy. Come to think of it, I have nver pulled apart a car/truck this old; even my '60 F300 was only 27 years old when I got it.

A good lesson for all older cars......everything can be gunked/dried/corroded.