Found the Wix filter and drained her. Thanks for the P/N because they were having difficulty finding it. No white build up or anything that suggests coolant mix, and nothing up under the valve cover suggested it either. I went ahead and drained all the coolant and ran clean water through it. The coolant that came out was just green, and looked exactly like the stuff I put in; no brown or sludge. I ran clean water through the system, drained it out, and besides a couple dead lady bugs and maybe 1 or 2 specs of dirt - there was nothing. I pulled all the hoses off and cleaned the electro build up off, and replaced all the hoses (except for the little short 3 or 4" one that goes from the pump to the block - that will be done when I get the pump off), and ran a couple longer heater hoses away from the VC (just looks nicer).
On top of that there is no white smoke. I've blown a few head gaskets and replaced them in my time. All had the giant plume of white smoke coming out the pipe, but maybe not all of these are indicative.
Tomorrow I will be driving out to my dad's shop where he has a whole line-up of tools to check compression, timing, etc. and see what's up. I also got a cheapo gapper so when we pop each individual plug out, I can check it for the correct space mentioned earlier, and probably wind up buying new plugs anyway. Thanks for all the help so far everyone. I'd like to get this miss sorted out so the motor doesn't rock at idle. There's not much point building a nice shroud if the fan is going to rock sideways and smack it.
Also, on top of that I ran the car and pulled the pcv elbow thing out of the valve cover. I put my hand over it and the valve compressed, and the idle speed dropped. Let go and it went up, put hand over - compressed, vacuum, and dropped. I'm guessing it's functional?
And yes Trailbeast, you're correct. It's a pertronix kit and is just EI, not the HEI system. When it still had points, the bad idle was a lot worse - A LOT worse. After swapping it it's more of a gentle rock, but the miss is still apparent. I've also been told by a few people that the carbeurator I have just sucks at idling. Could also need to be rebuilt.