FYI OM603 Cylinder head exhaust studs

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In the course of wasting several hours jumping to a silly conclusion, I made some measurements that someone somewhere might use. Stupid story follows the measurements.

#17 cylinder head exhaust ports(at least the one I measured):
M8 1.25 pitch threads
The exhaust manifold stud holes are drilled approx. 28mm into the head.
The stud is about 43mm OL
Each threaded end is about 15mm.
The middle shoulder is about 13mm.
The stud protrudes 24-25mm from the head.
The washers are 3mm thick.
The exhaust manifold thickness at the mating surface is about 10-10.5mm.

If you think YOU'RE dumb, you can read the story:

I'm replacing my cracked #14 head with a #17, which I had rebuilt. The #17 head was missing 7 exhaust studs, so I took them off the old #14 head. When I installed them on the #17 head, I just screwed them in until they stopped, just lightly hand-wrench tight. WRONG. This makes them go in too far. Those of you who have ever replaced an exhaust stud probably already knew this. I could see that the studs I had just switched over from the #14 head protruded 4-6mm from the head less than the studs that were still good in the new #17 head. I jumped to the brilliant conclusion that Mercedes, along with the other changes to the OM603 head, had made the studs longer. Of course not. The old studs were about 42 mm long, so I went looking for M8 studs 45 or 47mm long. (Dealer said if they could get them, it would take 3 days to 2 weeks). Failing to find such a thing, I decided to go back and remove and ACTUALLY MEASURE one of the good studs from the rebuilt #17 head. Same as the ones from the #14 head, or maybe a millimeter or two longer, not a material difference. DOH.

Moral: only screw in a stud as long as it NEEDS to go. And here's an idea. Figure out what that is BEFORE you start. If it's the correct length for the application, there will probably be room for it to go in too far. It's the torque on the nut that's going to hold it all together, which is why you are supposed to use the special self-locking copper ones.

Also, I ended up having to start the new nuts on some of the studs and screw them in like bolts.