kay! I should have left well enough alone, but I was in a work mode and I hate stopping that train! So I told y'all about the broken studs in the exhaust manifold, and I told y'all how I drilled them out with my drill press. I figured I would just tap some new threads into the holes, and throw some bolts in there, and just rock and roll! I don't have any taps that size so I took it down to AJs (my neighbor) 'cause he is amazing! He removed the heat riser for me and plugged those holes. Then we progressed to MY work... you know... the holes I drilled out!
I didn't have them straight (plumb) and they were elongated from the bit drifting. And AJ pointed out that you need to bolt up the manifolds to the block BEFORE you tighten
the two together, as they need to shift against each other a little, or you could crack a manifold. So he had to heli-coil the holes. Only... one of the holes was so bad the heli-coil(s) wouldn't take! In the end, AJ used Loctite Weld and put in a stud. So I nearly cost my son a manifold due to impatience, because I didn't center punch the broken bolts, when I KNEW I needed to!!
Here are some pics of the process. There is nothing that y'all haven't seen before, but sometimes it is interesting to see what goes on.
A couple of points of interest to me... the holes where the heat riser shaft passed through the casting had bushings in them. I would never had known that if not for AJ. I would have attempted to thread the bushings...
And AJ showed me a center punch set. Sounds like a small thing, but I had never seen what he showed me. I always use a center punch by guesstimating the center of the object. His set looked like they were made from pushrods, and they were in varying sizes to fit different sized holes. The punch would slide perfectly and snuggly into the hole and center automatically.