For Pre-A thru 356C -- We inventory US-made phosphorus-bronze valve guides in standard and in two oversizes for valves with 10 mm stems.

This 2nd oversize guide with an OD of 14,20 mm (.559"). Length is 63,50 mm.

Once installed, these guides have to be reamed to size to accommodate the stem diameters of the valves you are going to use. Note, modern-day valves slightly differ in stem diameter and in material from original valves.