New sending unit leaks at lock ring

Get the rubber gasket from DMT (I linked it in my previous post). Most of the repop gaskets are too thin.

You don’t need an OE lock ring either, although they’re easier since you usually don’t have to tweak anything. But even with the cheap repop lock rings you can bend that tabs on the lock ring to change the tension on the gasket.

I have used the spanner too, it can make things easier with the limited space available especially on the A-bodies. But most of them are pretty cheap and don’t fit all that well either. If they fit well it’s a good tool, but most don’t fit well enough to be worth it.