The fun never stops. In the process of mounting CMI big tubes and the head studs are interfering with the header flange. I was told it wouldn't be an issue to remove the head studs and replace with bolts on the lower 4 where they are interfering. I'm not too thrilled with doing that with new engines fresh off the dyno- any thoughts? I guess grinding into the flange might be an option. Pretty much the entire threaded portion of the stud (about 1/8th in) is in the way on every stud.

Machining the header flange would be my choice.

+1 this is what I had to do also

Cut the remainder of the stud that is sticking out off. Done it and seen it done many times for that reason. Or replace the studs with arp bolts in those 4 holes

I think cutting off the top of the stud rather than cutting into flange might be the way to go. I'd really hate to start hacking into the flange on the headers

yep common problem..i turn then down on the lathe.looks neater..

i removed the 4 bottom studs and replaced them with arp head bolts on a 1200 hp pro charged engine,no problems.

The're relatively mild engines but I hate idea of removing the studs to replace them. I imagine there is some sort of sequence to tightening them down that I'd ruin by pulling just 4 and replacing them. Don't even know what the builder torqued them to.

Replacing them one at a time is not an issue as far as the proper sequence.
You need to use the recommended amount of torque that comes with the head bolts.

I just grind the flange with a grinder. Doesn't get into the sealing surface. 2 sets and no leaks...