markjackson
Registered user
Lots of knowledgeable people on the forum regarding the R90S.![]()
But can any of them spot if this is an R90S or R100 cylinder head? Although Bings were fitted, the 'Bing' carb mount certainly looks newer than the rest of the head, and they are sitting on what I think are 90S barrels (albeit on late 81 R100RS cases) in a 90S frame.