[Henry Schmidt]

Leaks like this one are why we switched from Loctite 574 to ThreeBond 1104.

Clearly, the correct repair is to remove the heads and cam towers and reseal the offending sealing surface.

As for possible repairs, we were occasionally lucky with a suction technique.
Remove the engine, place it on the stand.
Remove the valve spring from the leaking head and wash the area with brake cleaner. It is necessary to clean both inside and out. Once the area is clean and dry, compressed air help the drying, you tape a vacuum hose to the outside of the offending area. Next you apply loctite flange sealant to the inside of the gapping area. Turn on the suction and pray. Give the sealant 24 hours to cure and test with light weight oil. The leak is not pressure fed so you can test your repair without running the engine.
Loctite 568 flange sealant might be a better choice for this process because of it's lighter viscosity and higher tensile strength.

Good Luck