thread sealant, petrol resistant.

Looking for thread sealant which is unleaded petrol resistant.

At work i have loctite 577 which is unleaded petrol resistant. But when i look at the data sheet, it says it is temperature resistant upto 150'c, but for petrol it says only upto 22'c (or i understand it wrong).

I also looked at sealant from Griffon Densitol. It says it is petrol resistant and temperature resistant upto 110'c. But the data sheet says it does not resist unleaded petrol.

So what to buy to seal fittings in a fuelpump, and fittings in a fuelrail?