Fuel Pressure Regulator Leaking

[1972BlueC20]

I tried installing an Edelbrock fuel pressure regulator recently because I wanted to get my pressure down to a constant 5.5 PSI since I'm running an Edelbrock # 1406

I got everything hooked up, but all the fittings I just installed were leaking fuel....not gushing but slightly leaking....everything was really tight....I removed the regulator completely from my truck and put everything back the way it was until I can get everything sealed up properly

I'm assuming I need some kind of teflon tape or thread sealer maybe?

Anyone ever had this problem?

Whats the best thing to use for sealing fuel fittings. They are 3/8 NPT