[KTL]

The #6 stud is one of thirteen that are M8x32. 32mm is the overall length, not length sticking out after it's installed. I have a bunch of junk camshaft housings that i've pulled the studs from. The lower valve cover studs are M8x35 and I have a bunch of them if you would like me to send one or a few or however many you want. No charge.

The #17 bolt is nothing special M8x45 length and a common 8.8 property class/strength. This should be easy to get at your local hardware store. I've found that Ace Hardware stores have a pretty good selection of basic metric bolts like these.