Sprint,
All alloy heads use the sleeve nuts on the rocker boxes.
If you have one without, it must have been changed by someone in the past.
Trev.
Thanks Trev
That leaves me a bit confused?
The 67-1549 that I have just obtained has the rear cly hd holes counterbored to take a sleeved nut, which I assume requires shorter studs in the inlet end of the rocker box, see photo.
My 67-1571, on bike at moment, simply has the same holes just parallel bored 5/16" clearance and uses std nuts and washers. and as a result the rockerbox inlet end studs are long, which is a pain as you have to remove them before you can remove or fit the rockerbox with the engine in the frame.
A friend has a 57 RR and 60 SR and they also have long studs at the inlet end and std nuts and washers, though I don't know what heads he has or if the rear holes are counterbored?