How do you choose? I watched a video today of a guy that used Aviation form-a-gasket to seal the oil pan, water pump and others. What is the difference between ultra black, grey, the right stuff grey, black , permatex blue, red I am replacing the gasket on my timing chain cover as well as my water pump to block gaskets.. I believe I used RED high temp permatex to do so the first time. I have also used the right stuff black for other parts. Is there a guide, spreadsheet, form that lists the applications for all the gaskets and the sealers that are needed and those that only need the gasket but no sealer.