Jon G Not gonna throw anything but have to downplay guide knurling,it just wears out too soon. In the case for our old castings looks like bronze walls are the safest and very durable. However iron guides have kept these engines alive until old geezers like us could take over, right ?? So I'm not afraid to take the chance and drive in new iron guides. I pressed in a set a while back,lot better to use a big hammer and driver to fit. they're running using fresh 350 exhaust valves hard seats ,hard button on the stem in the 235 1948 splash oiler. Gonna go get ready to haul and spread white rock now !!
