I have an exhaust valve clearance way too tight (21/27). Its shim size was no longer visible so I brought it to a shop and they measured it to 1.63. If everything is correct it means I need a 1.00 shim to bring it back to spec, but there are no shims that small! Going to get a micrometer and recheck everything myself but what sorts of valve problems am I looking at if the smallest available shim (1.2) will not bring it back to spec??