Hi Britt
I have used a step stud to repair my first 914, if the damaged hole is not too bad, its a good option.
People will argue the fact that the studs walls are not thick anough, and a heli coil is better for expansion and contracion. If you ever workrd on a damged heli coil, you know what a pain in the ass that is.
I retapped the head in place, used step studs, and heated the heat exchanger to notch just a tad more clearance around the nut area. I find that if you are not carefull with the new exhaust nut and stud, it can be damaged on assembley (trying to fit a fucking wrench or socket on it). Everything was tourqued down evenly using aviation grade brass nuts.
Worked for me
Later