Hey, Thanks a lot for the response. See below for answers:
When I reinstalled my stock intake, I did lay down a 1/8 bead of optimum gray around the coolant openings on both sides of the gasket to help further seal, no leaks. - Did this when installing the intake
When you re-installed the intake, did you make sure to FIRST torque the draw bolt in the front that mates the intake to the timing cover, with the O-ring seal in between? - Yes, did this as well.
You have to torque that draw bolt first to pull the intake forward a small amount and make that seal between it and the timing cover. After that is torqued down (official spec if 15 ft/lbs, but I did it by feel and it was fine - don't overdo it, that bolt snaps easy), THEN you torque down the intake manifold bolts to 40 lb-ft. - Did this as well. Torqued them in sequence several times.
It also doesn't hurt to apply a bead of RTV at the mating surfaces of where the timing cover meets the intake, it's commonly pitted, at which point you can't fully rely or trust that rubber O-Ring. - Did this as well.
As for the thermostat housing, if it leaks again, try it with just straight RTV. That's how the service manual recommends to do it, after all. - Good to know, but I can find no areas that are wet/moist anywhere near the thermostat housing.
And then for the water pump, you mean the crevice between the timing cover and the block? - Yes!
I'm assuming this is a Pontiac engine. - Yeppers
Coolant in that pit between the timing cover and block is usually because of the previously mentioned O-ring seal where the timing cover mates to the intake. A leak coming from the timing cover where it mates to the block would be an oil leak, not a coolant leak, and a coolant leak from where the water pump mates to the timing cover wouldn't end up in that crevice. - Hmm, Interesting. Everything above that area seems dry as a bone. No wet spots or anything and I only see coolant after it sits for several days, maybe a week.
If it were the thermostat housing, usually those leaks will end up in the front flange of the valley pan and travel all the way back to the distributor valley during driving. - Never had that issue.
I just find it weird you keep springing these leaks. - Me too!!!!!!!!!!!!!!!
You said you aren't overheating, but are you losing coolant from anywhere else? Like, a lot? - No, only when it sits for a week or so and once it hits a certain height, it stops. Before when it was leaking from the top, that crevice would fill up and the coolant would spill over onto the garage floor. Now it just sits at that level, which I assume is equilibrium with the coolant level in the block. That's where I got the idea that it was coming up out of the front of the block/timing cover.
Because unless these seal failures are due to repeated installer errors, then SOMETHING is overpressurizing your cooling system. What radiator cap do you have? - O'reilly's special. I don't think that is the case because the hoses don't seem to balloon or anything. Radiator seems to be doing an awesome job as the coolant temp drops dramatically by the time it exits. (I can grab the lower hose going back to the engine.) Annnd the leaks don't happen when running, only when it sits.
Maybe I just need to go grab and LS engine 
- I can post some pictures, but not sure how that works since photobucket isn't what it used to be. I could definitely try a new cap, but if it leaks when it sits, would it really help?
Okay, the intake install clearly isn't your issue, then. Maybe it is the water pump. I guess I can see where a leak from the *top* of the water pump would run back and land in that crevice between the timing cover and block. Honestly, the only time I've ever had coolant in that crevice is because I made a mess and spilled a bunch of it when servicing the thermostat housing. Even when my stat' housing leaked really bad, it never landed in that crevice, it would drip into that depression behind the front flange of the valley pan. Basically like this:
When you did the water pump, did you install the two gaskets dry? Generally, most people use RTV to support the gasket seal for the water pump. Ultra black is a good one for that. It's pretty necessary, since often the divider plate isn't always going to lay 100% flat against the gasket surface of the water pump, so you need the RTV for extra insurance beyond the bolts flattening it out as it's torqued down since it's thin metal. This is especially after beating the divider plate to tighten the clearance.
A radiator cap is a super simple thing to replace to see if it's the problem. I'm guessing you don't have residual pressure in the system after the car cools down, right? Like, once the car is cold after a night of sitting, you can easily squeeze the hoses, and removing the radiator cap doesn't result in a "hiss" of pressure? That may happen for a couple drives after you do a major service on the cooling system that involved lots of trapped air, but it should stop eventually.
Also weird that the leaks only occur when the system is under no pressure... you may have to do some fine-tooth sleuthing to see if you can find trails of coolant. Usually you'll be able to find them. Or pressure test the system again.
Or, think really hard about if you accidentally spilled and made a mess with coolant after servicing the system. Maybe that's all that coolant is in the crevice between the timing cover and block!
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