The last thing i would want to see is the Cylinder Head damaged ana you get fed up with your +2.
When the Cylinder Head is at the Machine Shop i suggest that they remove the Exhaust Studs also.
Then you can fit new Exhaust Studs and screw them into the Head by HAND with lots of Copperslip on the threads.
Assemble Manifold with spring washers and BRASS NUTS.
Before you fit the Head make sure all the Studs screw into the Head by hand the full depth.
Fit the Head WITHOUT the Studs so they do not get in the way with the Exhaust Manifold.
Sorry to tell you how to suck eggs but after 45 years working on Twin Cams i am starting to know the ropes
I hope your Heath Robinson bodge holds out during the drive.
Alan