Technical 364 Nailhead: tell me about the seal around the valve stem

Please.

I have a new Best Gasket set for the 364 Nailhead, 1957. It does not include seals for the valve stems.

The existing seals are not in bad condition and could be reused, but I have a hard time seeing how they are necessary.

 

That seal is to help keep oil from getting past the valve stem and guide and into the combustion chamber. I know it’s not much but use that or have the guide cut for a positive seal

 

If you've got enough room between the valve stem and spring, get some universal umbrella seals and slip them on..