Jerry, why not have modern bronze sleeves installed into the existing guides? That is the method used by competent machine shops in reconditioning heads. Bronze guide liners are also used in manufacturing aftermarket heads. They are in the Edelbrock heads I bought for my street roadster.

That may be more cost effective and will provide a superior finished product. The trick will be finding a person to do it competently, especially if you are in a rural area. I moved from an urban area of California to a rural area and the concept of doing things properly simply does not exist here.

Ray