When I was building a lot of cylinder heads, we bought thin wall bronze valve guide sleeves and reamed the guides .030" oversize, pressed the sleeves in, and reamed the ID to fit the valve stems. The reamer had a reduced diameter pilot that centered it in the ID of the original guide. It was quicker, and somewhat more accurate than replacing the entire guide. When boring guides out completely and pressing in replacements, there's always a danger of cracking a head, and/or getting a guide severely misaligned with the valve seat. K-Line, Goodson, and a few other machine shop supply vendors have the sleeves, and installation kits for them. I can usually find sleeves at bargain prices on Ebay. The 292 will need 0.343" diameter sleeves. (11/32" valve stems)
Jerry
