... the oil pan received Duplicolor Cast Coat Aluminum to help monitor for oil leaks, there bloody well better not be any!!!
Here's how to guarantee no leaks from an F-series oil pan:
1. Bottom of block and oil pan flange antiseptically clean with no trace of previous gasket.
2. Check oil pan flange for level and straightness; correct with large flat drift or similar and anvil if necessary. Many oil pan flanges have been bent by previous owners prying them off.
3. Use only the factory Toyota one-piece cork gasket; accept no substitutes!
4. put a very thin coating of good FIPG all over both sides of the cork gasket. I much prefer the Toyota FIPG over all others but it's expensive. The manual only says to put it on the corners, but in my experience all the way on both sides is the way to go.
5. DON'T OVER TIGHTEN THE OIL PAN BOLTS! The torque spec is only 91 INCH-pounds as I recall, i.e. 7.5 ft-lbs. If you crank the bolts down like you normally would most other gasket surfaces, the cork gasket will deform and squish out and you will have leaks. Use an inch-pounds torque wrench; your foot-lbs wrench will not be accurate at that low of a setting. I have one you can borrow if need be.
6. Tighten the bolts gradually in a cross-hatch manner; finger tight then only to the torque spec after that.
This is how I do it, and my F engines don't leak a drop.