I number of years ago I had I head I was redoing that, for whatever reason, we were having a very difficult time getting the original guides out for replacement with new. Ended up using just a little too much pressure and broke the casting, instantly turning a perfectly good head into a boat anchor. From that point on I have opted to have bronze liners installed into the original guides and then finish the guides to a proper clearance with respect to the valve stems. It’s slightly more expensive, but I think yelds a better end result with respect to oil control on the stems.
