Cmsnl.com has charts that will show you what's needed and where. With the part number order where easiest to order.
Important to not use too long.
I have seen lenght of 22mm that can be too long not letting cylinder to mate case.
I ordered extra since they are not expensive and will easily be bent. Lenghts of 15, 18 and 22mm, different years different lenghts. The 8pcs for cyl- head (special something 14 mm long) need rubber gaskets around usually supplied by complete gasket kits (these 8 with gaskets not used with MLS head gasket). Important to measure that they will not bottom out and not let head gasket to compress and seal.
I have grinded some a little bit shorter to fit.
Also order the 8mm dowels for cam holders and various covers.
You need 12 or more if order all new.
If you have plans to remove oil pump, buy rhose 3 dowels too. They are easy to damage. I got 6 of them sent to me yesterday. Good to have.