Finally got my wifes Monte Carlo out of the garage after a month. Replaced the head gaskets, lower intake manifold gaskets, and plugs. It had been mixing coolant and oil. Not good. Runs like a champ now.

With the garage opened up, I picked up where I left off with the Caddy. Got my FSM manuals now, so I followed the diagnostic tree for my DTC73 / P1571 (ABS/TCS lights), 2nd gear start issues. Turns out it's a bad EBTCM. That doesn't suprise me much, as when I pulled off the lower radiator hose almost a year ago, it filled up the EBTCM electrical interface with coolant, and I pretty much let it sit that way (un-noticed) for 10 months until I went to put the car back together. When I went to plug in the EBTCM connector, I noticed all the coolant in the EBTCM. I figure that must have been a bad thing, seeped in around the pins, and trashed the circuit board in there. I'll take it off the BPM, see if it can be disassembled, circuit board cleaned, reassemble and see if it works. Otherwise, I'm gonna have to find an ebay score for a new one, cuz I sure as heck aren't paying GM $800 for a new one.