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Do you guys have any pointers or tips to help keep this neck from leaking between the gasket?

Form-A-Gasket Type 3 Aviation

Affectionately known as the "Brown Shit"
It's in the same family as Anti-Seize...It works awesome but gets on everything and is a pain to get off. I have never had a failure with it. Use lacquer thinner to get it off your hands etc. For your shiny engine, use sparingly on all (upper & lower) surfaces.

Murf wrote: ↑Wed May 28, 2025 5:23 amForm-A-Gasket Type 3 Aviation

This. It is a mess you need to clean afterwards but guarantee it works.

From FB I got all kind of suggestions from using Type 3 Aviation as well as others. The base area where the neck sits on the head was not too smooth. One suggested I take it to a machine shop to have it milled smooth. Sorry but I am not taking the head off now.

I decided to use JB weld metal filler to put on the head where the rough places were and sand it down. The I decided to go with the Indian Head shellac. Right now I am letting it cure as long as I can before I put coolant back in. I will report back.

Hope it works. The type 3 would still take care of it. It has the consistency of extra thick molasses.

Straight-edge your mating surfaces to confirm they're smooth might help too.
Gary

Type 3 is the bomb for that.
And here is a tip straight from Permatex for clean up. Use isopropyl alcohol. Instantly takes it off your hands. Easily cleans up extra pushed out around part. With a soak, easily cleans the surface when you take it apart years later.
After decades of using it, I can attest to its effecacy.