Z1OwnersClub GB

Thanks to help and advice from people on this forum my Z1100 1981 A2 (1?)-engined trike is now off-sorned and MOT'd. Compression pressures are only 112-115 hot with an open throttle, but this is after glaze busting and re-ringing so they will improve, I hope.
I can't see a torque figure in the Kaw or Clymer manuals for the 8 exhaust pipe-to-head clamp nuts.
The four new soft gaskets must be squashed to gas-tight but the aly head is 31 years old, so I would rather use a recommended torque figure if there is one.
Brass nuts are or were commonly used in this position but I haven't noticed them on bikes (unless they have been chromed). Perhaps brass ones wouldn't happily take the required torque?
More advice please.
Thanks.

If there's no specific figure quoted you could just use the figure indicated for the stud size should be in the Kaw manual somewhere.

Yes I could and I will if nothing more comes along.
I thought that I might as well make use of the wide Kawasaki knowledge available here.
For instance I am hoping to be told whether, after all these years of heating and cooling, the alloy of the head becomes softer or less tolerant of excess tension.
Thanks.

Just 'nip' them up by hand, if the exhaust still blows, 'nip' 'em up a bit more.