So my mallory coil and fuel pump both decided to die the same day on a car thats been under resto forever. Started fine the week b4. The coil is gone but the fuel pump is fixable.

Pump is a Mallory comp 140. I narrowed the problem down to the old style plastic plunger sticking in the bore. (now they use brass for that plunger.) After micro sanding the plunger it slides nicely. So now I need a sealer to coat the threads of the internal regulator set screw. That screw leads directly into the pump body so if it isn't sealed it will leak fuel. Teflon tape is an option but not a great one. I have rectorseal 5 which is gasoline approved but I don't know if it can go right into service or I have to wait. What are you guys using to seal screws that come in contact with fuel? Keep in mind this has to be a thread sealer that allows movement in case I want to change the internal regulator pressure.

Thanks,
Dave

I'd think the can of Permatex #3 the black goo with the brush applicator would be suitable. Likely you could Google for the mfr specs of it, if it is fuel resistant or not

Hylomar Universal Blue or the equivalent, Permatex Permashield.

Both are Non Hardening and Non Setting and can be put in service right away. Resistant to all fuels and you won't need to brake out the 1/2" breaker bar and torch to disassemble

Tip; a very little bit goes a long way.