What's happening here is your are trying to seal a straight thread. That was NEVER meant to be done.

Studs with a shoulder between the 2 threads or...

Silicones is your best option here.

Teflon tape, pipe paste, pipe thread sealant are for lubricating and sealing tapered threads.


69 Super Bee, 93 Mustang LX, 04 Allure Super