Hi, Boris.
The exhaust stud has a different thread at each end, which might be confusing matters. The cylinder head thread is M8 x 1.25 torqued to 15Nm while the exhaust nut thread is the M7 x 1 you mentioned earlier, tightened to 24Nm.
The intake manifold stud, on the other hand, is M8 x 1.25 at each end.
You can see the different threads in these photos:
Exhaust stud
Intake stud
Hope that helps!