Gang,
Quick update on my rusted freeze plugs issue I posted yesterday (thanks for your responses). We pulled out the engine, removed the manifold / heads / camshaft to get a real good look at everything. Luckily, the rust was contained to just the water jacket....but boy howdy, is it every rusty . When we pulled the 6 side freeze plugs, there was probably 1/2 inch of "rust dust" around each plug hole. Some of that I'm sure was from the plugs themselves, but some must have been higher in the block. The coolant holes in the heads are also pretty rusty. See attached photos if you're morbidly curious.
Here's my planned next steps, please let me know if I'm smoking crack or if you have other suggestions:
1. I'm going to vacuum out all the rust dust I can reach, and then use wire & bottle brushes to try and loosen up as much rust as I can - I might even put a gun-cleaning brush on a drill to get the small holes. I'll vacuum at the same time and take care to keep dust out of the engine guts.
2. After a good vacuum job, I'll seal up the engine top and then blow a lot of compressed air through the water jacket.
3. I'll take the engine outside and try to run some plain water and perhaps a little vineager through the coolant areas for a first initial flush - again, taking care not to get junk in the top of the engine.
4. After installing BRASS freeze plugs, we'll reassemble & reinstall the engine. We'll either use an older "sacrificial" radiator, or just bypass the radiator. We'll fill it full of some type of block flush chemical (like Thermocool) and let it cycle through for a few minutes, before shutting it off and leaving it for a day or two.
5. We'll drain the fluid, probably repeat the flush step until it looks clean, before putting the real radiator & coolant back in.
6. We'll check the coolant again after a few weeks.
Here's the moral of the story and a lesson learned for you: don't leave an engine block empty and assume it is dry, and leave it outside for 5 years sealed up except for the radiator cap!