AJS & Matchless Owners Club

Hi All,
I am replacing my exhaust valve OEM Part No 042868 ( later Thick type as its a 66' production engine ), and just thought i would put a Mic on it to check the stem size of the new and old one, - the stem diameter is 8mm (315 thou). I'm sure i saw somwhere on here tht it was quoted as 8.5mm. This may be for the 350cc ? but the 250 late CSR is 8mm. Thanks

042868 should be 1.187 head diameter, 0.342 stem , 3.996 length and is 250 CC G2
042033 for 1960 G5 350 CC is 1.190 head , 0.310 stem , 4.00 length