Can someone measure the long engine mount bolt that bolts the pegs on? I am guessing it is m12 but don't know the length.
On my '78 CB550K, this is actually a long stud with M12x1.25 threads on both ends, with hex nuts and lock washers to secure the foot peg brackets. The end-to-end length is very close to 14 inches, or about 355mm.