First, super big thanks to everyone for the advice with the hoses and expansion tank. I wrapped up that job today, with all new radiator, expansion tank, thermostat, heater valve, and hoses. I put the level sensor in also but need to wire it up to the dash later.

In the meantime, I am getting some instability in the idle (even just sitting in park fully warmed up) and the idle bounces when I drop my foot off the brake. So, I figure good time to do some additional maintenance. Here is what I have planned:

clean throttle body (replace gasket)
replace pcv breather nipple
replace oil trap / separator
replace brake check valve
blow out the hoses connected to each to be sure no plugged hoses

while I have the throttle body off , anything else I should be cleaning, etc., as preventative maintenance?

It all looks pretty simple from the FAQ and other walthroughs. Any advice or warnings? Things to watch out for?

Thanks again.

If you have an EGR valve, now is a good time to clean it. There'll be a valve with a (rusty) tube running from the exhaust to the valve, then one to the back side of the intake manifold in among the vacuum nipples, downstream from the throttle plate.

You might also want to replace the intake manifold gasket, but that seems unnecessary. Same thing with checking the TPS/throttle plate - just make sure that the TPS clicks when you first move the throttle, and that the throttle plate is actually closed (within a millimeter) when the TPS first clicks while closing the throttle. Generally, it's a good idea to leave well enough alone, but someone may have adjusted it at some point. This usually results in a funky idle that isn't the same speed all the time.

Good luck!

PS I would recomment cleaning the nipple that the PCV/breather connects to (the plastic one in the tube, if you have one) and the one on the manifold. If you have a flame trap, now is a good time to relocate and/or service it.