Hello! I'm stumped and needing help, so I appreciate any guidance you fabulous folks can offer. As a DIY'er, I have turned to this site many times in the past and pretty much always found the information I needed but not this time, so far. Here's what's up:

There is no water in the oil or transmission fluid -- no coffee or strawberry milkshake. There is no smell of exhaust in the radiator, though I didn't do a chemical test. However...

I've had this truck as my daily driver about 3 years, and I had been losing coolant slightly for about 2 weeks, but I chalked it up to a hose going and figured I'd tackle it on a weekend very soon and swap out all the old hoses.

Then Murphy struck. I parked after a short trip to church and back last Sunday, and when I shut the truck off I heard quite a hiss -- I turned the key back to "on" and the temperature gauge was at my normal, a little under half-way. I popped the hood and noticed some steam, but not a lot -- about like a tea kettle simmering, and I couldn't visually pin down the source listening to the hissing. It almost sounded like it was coming from the center of the motor. I didn't see any leaks underneath at that time. So I let it cool a couple hours and then filled up the radiator with distilled water to look for leaks, and it took about 1.5 gallons. Lo' and behold! after 15-20 seconds, there began a steady trickle from the bottom of the motor side of the transmission bell housing where it meets the engine, almost square in the middle but an inch or two to the passenger side. I couldn't get any better angle to see the source from the top, side or bottom.

By the power of the internet and great forums such as these, I determined the problem must of course be either the intake manifold gasket or the bypass pipe that runs underneath the intake. After a fun-filled couple of hours today dismantling the top of my Little Engine That Could under an old oak tree in my dirt driveway in the middle of a Florida summer, dodging mosquitos and intermittent rain showers, that's not the problem. The gasket definitely needs replacing due to oil and minor water seepage (need to figure that out, too, because I'm getting some oil blowback into the rubber intake tube going to the throttle body LOL), and the top of the "V" is orange and rusty and crusty looking, but the sensors look to be in great shape and neither the gasket nor the bypass pipe showed any signs of water when I slowly started to fill the radiator... and still got the same steady trickle down the back of the motor somewhere, before I could even see any water in the intake manifold channels. None of the hoses are leaking either, that I can see.

I've had to replace one failed freeze plug on the passenger side about 2 years ago, and two of what appear to be freeze plugs under the intake look pretty rough. I'm thinking I should do those while I have the top apart (maybe it's just funk from the manifold gasket seep?). However, the "V" stayed dry (no pun intended), despite the trickle out of the rear. I have also heard rumors of freeze plugs on the back of this motor on the firewall side. I was able to see one that faces the firewall on the driver's side tucked in behind the exhaust crossover, but it's shiny silver and no leak. I couldn't get to an angle where I could see a freeze plug on the firewall passenger side. Is there one there?

Please tell me I don't need to pull the motor (unless that would be a lie). It's only got like 280K miles on it... it's barely broke in!!!

Help! I've heard the factory manual recommends against running these 5VZ-FE motors without coolant.

Sorry for the novel, but I wanted to provide as much information as possible. My sincerest thanks in advance for any help (or even comic relief at this point) you can provide.