The crank of the said engine needs splitting and the 125mm conrod replacing with the r27 variety. The bobweights are the full late 26/27 type, but one of them has two lugs cast into it, the size of the top of one's thumbnail, and in the area of the crank-pin.The lugs in question can be seen in the parts list diagram. The other does not! Does this mean that the crankshaft has been made up from two halves from both r26 and r27? how can I tell?
Best wishes, Graham Sidey.