Re: broken threaded rods
Depending on how deep the studs are in the case, you might be able to grind a slot in the end of the stud and turn it out with a screwdriver. The studs just screw into the case.
You'll need a Dremel tool or similar type grinder and a cut-off wheel to grind that slot.
You don't need to use studs. Any hardware store should have Allen head cap screws. You'll want 6mm X 1 thread and you'll have to determine the length.
If you've never used an extractor (Easy-Out) you'll need to be very careful and make sure you get the hole that has to be drilled exactly in the center of the old stud. This is so you don't drill into the threads in the case and damage them. An alternative is to take the engine to a machine shop and let them do it. Good luck.
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