I recommend reading through the "Complete Engine Sealant Thread":
http://forums.pelicanparts.com/911-engine-rebuilding-forum/284737-complete-engine-sealant-thread.html
There is some "spirited discussion" in there, but it's a worthwhile read. Lots of tips in there regarding how to avoid leaks on a rebuild.
Looking back on my rebuild, my best tips are:
- Case prep is important. Verify all your squirters work, all the galleys are clear, no chips, etc. Make sure the case is spotless and everything works before you start assembly.
- Plan ahead relentlessly; make checklists for everything and stick to it. Break it down into small assembly steps. Validate the checklist and then do the assembly. Don't get in a rush. Don't take shortcuts. Stop when you have questions and research. It's better to let things sit for a few days while you figure it out than to wake up in the middle of the night wondering if you did something right/wrong.
- Keep everything clean, organized, packaged until ready to clean and install, and then do more cleaning.
- Definitely upgrade the oil pump and do the case by-pass mod. This is one of the keys to a happy, cool motor.