when it says like
M6x25
does the 25 mean the length of the stud?
Thanks
yes, if you go to a hardware store, that's what you'll see on the packaging. Very rarely

will it mention the pitch unless it's using a nonstandard pitch. M6 usually has a 1mm pitch though.
The new blocks have cylinder studs that are 8mm X 1.25 pitch
Yep, thats in there. 1.25 pitch is standard pitch for 8mm studs.
Updated the parts list with the numbers from the official parts list. Doesn't seem like they're correct as nearly all the bolts and screws I have are different lengths. Still, it provided some good information such as the clutch and sprocket nut size.
Can anyone confirm the small bevel gear screw being M8 with 1.00 pitch? I mine stripped out and I cant get a good measure.
Using
www.nuttybolts.com you can buy all of the mentioned hardware (well... most, actually). judging from the fact that the hardware kit SBP sells uses a different kind of stud for the rear mount than the front, I'm assuming they order from this site as well, because they don't list a hex-stud with 70mm length (the one they send you is cut from a threaded rod, most likely, same with their head stud kits).
To get a box of 100 of each of the different kind of bolts you will need, will cost around $65. If you buy just enough for one engine it'll be about $9. As a comparison, SBP sells 'em for $10 so... just buy from them and get all the right sizes.