? Radiator Top/Bottom Tank Surfaces Pitted

What is your experience with situations like this? Will the new gaskets and gasket sealer prevent leakage OR is some planing (machining) of the surface on both parts necessary?

I have done several things depending on the amount of pitting.

First, clean ALL the rust out of the pis to bare metal, using electrolysis or media blasting.

You can skip the de-rusting if you plan on machining the surfaces back to flat. Once blasted, you can either use lots of Permatex (almost always works fine) and sometimes two gaskets, or treat the surfaces with a quality leveler like fiberglass resin or JB weld. Sand or machine back to true.

Having everything clean is important so the filler bonds and is not lifted by subsequent rusting. I usually clean with electrolysis, then wire brush to bare iron, then prime and seal with a quality epoxy primer.

I suppose you could even fill them with lead type body solder.

Since the "B" is not pressurized, you only have to hold an anti-freeze mixture, so there are many sealants that will do the job.

Frank