I am inclined to believe that the "new" studs that I bought were indeed special ordered by a major Nascar builder.

On another note, I dont believe that Milodon studs are broached.

i'm no F1 engine builder but finding trash in the engine and parts crashing into each other breaks rules # 1 & 2 in my book. my father summed up engine assembly cleanliness when i was just a kid...he said "you can't get an engine too clean".

i've never forgotten those words.

I'm pretty bummed right now but I agree with everyone it needs to come apart. Hopefully I can get something resolved with them. They are a well known operation, perhaps they will stand by their work.

What ever happened with the main stud issue? I had my machine shop line hone my engine and I went to studs. Low and behold I have the same strange setup of main studs! Six points on 1,2,3, and 4 and 12 points on number 5. What gives? And the thread engagement bothers me too. I don't want to touch the studs because I don't want to mess with it since its been line honed.

That's the way it used to be, the #5 has to be 12 point to clear the seal retainer. You may also have to shorten the studs slightly to clear the pan. I have never seen a set without the stud protruding completely through the nut, but I would not have much proble using a set like in the pics. I would not back up the studs in the block, the thread engagement there is more important if the block has been alignhoned and because of the material. The nuts will not let go if they are only a little short.

Never mind, somehow my mind played a trick on me once I saw this thread and I suddenly remembered a thread engagement issue with mine that did not exist. I have quite a bit sticking out past the nuts.

I put an oil pan on the block to catch the oil that I kept coating the bores with and haven't looked at the lower end for a while.

I do have the six point nuts though, with the 12 points on the 5th main, just in case anyone else gets this and wonders if they got an old set or something. Mine was purchased around April of 2012.