While working on my car I noticed a header bolt is missing. Tried to order a couple but they are back ordered from Germany. Anyone use something else or know where to get some quick?

 

home depot grade 5 or grade 8 metric thread works fine

 

Take a similar factory bolt out and head to your well stocked auto parts store and see if you can get a bolt that is the right diameter, thread pitch, that you can use while you wait for the factory bolts to arrive.

The replacement bolt may not have the same style head on it but as long as it fits/clears and you are sure you can get a wrench on it.

Watch the length! Do not think you can use a "slightly longer" bolt. Often car makers have custom length fasteners and a slightly longer bolt may bottom out in the hole and when tightened down crack the head.

 

Get some ARP locking fasteners it will prevent anymore from backing out. I would coat the new bolt in copper anti-seize.

 

+2. Anti-seize as well.