I need to get a new chain for my 77 F2 . A new o-ring 630 will cost me the same as a new 530 o-ring and sprockets . So a no brainer really , but if I get sprockets for a 77 will they just be k7-8 specific and not fit the F2 or will the front sprocket fit no matter which way it attatches ( single bolt or two with plate ) and all rears are the same pattern ? So can anyone help me out here