Thread chsing is not thread cutting. A tap or die will chase if need be. It will also cut all the threads off if you let it. I use a cut off wheel to make any bolt a thread chase type tool. That and a bit of grease will prvent chips from getting into the intake. Just watched a nice youtube video. A guy put a bolt and 2 nuts togethe. Drilled the junction on a drill press. Removed the nuts and has a tap like thread chser bolt and 2 thread chaser nuts(die) That is about as cheap and easy as can be. If the hole is in fact stripped. Then an insert is the way to fix it. Step type studs can be difficult to find and cost some too. The problem is different if you are fixing a side mounted intake(inline six) or a top mounted intake Most V-8. But if the issue is with the top mounted carb, then that is the same. One will need to drill or chase into Iron(the head) the other will need to drill/chse into aluminum(after market intake) or iron(Stock). It is different working on those 2 materials. Iron is easy to tap/ chase. Aluminum is a lot softer. Keep it straight and go slow.
