I hate to seem to disagree with anyone named Carl, but you might be able to do a fair job of flushing the system without such a compete tear-down. Keep in mind that dinosaur dung settles to the bottom of the block and even towards the back of the block - away from the radiator. You will come a long way by removing the rear pet cock down under the throttle linkage and steering shaft.
Most of those old engines will be so plugged up that nothing will run from the pet cock hole even with the spigot removed. So you need to go in with a piece of wire, like clothes hanger wire, and dig around in that pet cock hole until you get the primordial muck to run out. Keep the water running while you dig until the water runs clear. Then pull the freeze plugs and continue the process.
If after all this you decide that Carl with "C" was right, then every other part of the engine is probably in rough shape as well, and you might as well tear it down.
Have a great time!
Karl
Well I had removed the drain cock from the left rear of the block.
I probed around a little sludge came out.
Then with my son we took out the thermostat and put the upper hose back on. Then with the radiator cap on my son applied air pressure to the over flow tube while I re-probed the drain cock hole. A little at a time more would start to flow.
As it appeared as the dam would burst I told my son to stop the compressed air but alas the dam burst.
Oh the humanity.
I had to clean my sun glasses off.
I had bought a bottle of prestone radiator flush. Though I wanted to drain out as much stuff before I used it.
So when I get the time I will use the prestone.
Thanks to all that applied. And I like that Tide Detergent idea.
