[sammyg2]

Teflon tape is evil. Only use it on plumbing. No mechanical uses, ever. If you absolutely need to seal a low temperature application, use Teflon-based pipe dope (paste).
DuPont doesn't allow Teflon tape's use on the machines that make it.

paint the threads of your injectors with milk of magnesia.
No galling, no contamination, no problems. Same on your exhaust studs.
Use it on anything that can get over 400 degrees.