Better make a road trip and find a real machine shop!!!! Studs need to be put in correctly at a precise angle and set to the correct height. Not real familiar with a 348 head, but I would also imagine the stud bosses are going to be cut down some and machined flat, especially if you are installing rocker studs with a shoulder!!!!

Should be done on a cylinder head machine, can be done quite easily on a vertical mill, and if you know what you're doing even on a mill/drill machine.... As with many things automotive, there are more ways to do it wrong then there are ways to do it right!!!!