^ This - I ruined a set of TSE's inconel studs because they bottomed out before getting to the proper seat depth. It wasn't a failure due to the studs as it was improper seating depth. I had to drill and time-sert the flange to get them all the way in, after that, no problems. I think it was 15 or 17mm depth.

 

Luckily on the new manifold the holes are straight through so I'm good on the threads.