I came across someone selling a SRM refurbished single carb 9 stud head. The casting number in it is E3925. I have a data sheet from postdiluvian http://www.postdiluvian.org/~mason/moto/heads.html which indicates that it could be anything from 1963 - 1970. However there are 3 different part numbers shown for 3 periods within those years. That would be differences in the guides I suspect, as the part numbers would be shown as assemblies in the parts manuals. The main question is will this head fit on my 72 Bonnie? Physically I guess it would but what are the implications of the different guides? Indeed, does anyone know what the difference might be? The seller does not know what the head came off originally as he is only selling the stuff for the widow of his mate, sadly.
Last edited by TriVin; 08/09/139:56 am.
Dave Tiger 100SS 1966 T120V 1972 Vincent Comet 1952
I suppose you are aware that the '63-70 9stud heads use a different rockerbox and head bolt arrangement than the '72. Also the early heads have push-over exhaust stub. If you are determined enough and solve those, you'll need an inlet manifold to suit.
If the year numbers are there then I believe that if it says 66 it would be for a 67 model, etc.
I thought that the oil in frame heads have some smaller holes by the large centre studs where the rocker boxes fit. Also, you would have to make sure that the cutouts for the top of the pushrod tubes are the same as on your current head.
Last edited by dave jones; 08/10/138:48 am. Reason: added another sentence