Freeze plug problems

[1967 4K]

I’ve been reluctant to tell this but it has worked in my engine I had done in 2005. The engine builder told me before I run my engine to go to the auto parts and get one tube of the old time silver radiator stop leak stuff that’s been around for many years and put it in the radiator. He said it worked to help seal the freeze plugs and they would not give me any trouble.
His name is Sherman Gerlach, I always listened to him. I sure miss my friend.