I used the cork, and it worked fine on my first go round install?
Stock heads though. This go round I didn't have that option so I permatexed it. Works fine too.
Plan on ish to go wrong, and take longer than you thought lol. One thing I found is that if you take the battery out, you can set your power steering pump in the tray without removing any lines. Pretty sturdy and out of the way over there. Mine leaked there though, so leave ya some rags.
Also, study your accessory brackets very well. It took me a while to figure out how in the hell they go, and I never found any pics to help. If you still need help putting em back on, I'll snap some pics or try and word it for you.
Other than that, bag and label everything you take off. Label the harness too unless you know it well. The injectors are easy to figure out (don't worry about labeling those), but even though it can be figured out, it just makes life a bit easier on the assembly.
Good luck and if you have any questions drop a pm.
EDIT: Oh yeah, 5spd gt wrote an EXCELLENT install guide for the job. I didn't follow it to the letter, but I read through it several times beforehand, and used it quite often as a reference. The job sounds more menacing than it is, but it isn't a cakewalk either.