Set of 4 studs, washers, nuts
10mm 5/16 unc thread into manifold.
12mm plain shank
15mm unf thread
5mm hex wind in shank
The thread into the manifold is 5/16 unc and the thread on the top to hold the carburettor down is 5/16 unc. There is also a hex section on top of the stud to wind the threaded section into the manifold.