These guides are finish ground and made to size required to order, so there will be usually a 1-5 day delay from date of order before they are depatched..
+0.002 inch (0.05mm) over standard size Colsibro material valve guide A50 and A65 1971 to 1973 oil in frame cylinder heads, see information in technical about sizes.
Valve guides measures 0.5035 inch (12.79mm) diameter
Colsibro material is a copper nickel silicon alloy, and is second to none as valve guide material. Has high wear resistance and heat conductivity, and the lubricity prolongs valve stem life, if used with our Plasma hardened valves makes the best combination for longevity service life.
Valve guide after fitting to cylinder head must be honed to ensure correct valve stem to valve guide clearance.
Note valve guide sizing, A65 cylinder head guide hole is 0.500inch (12.70mm) so standard valve guide is 0.0015 inch larger (0.04mm) Check valve guide hole and if you need oversize valve guides, see our oversize guides listed.
