Hi Hans..I can't tell you the length from memory, but you can use stainless without problems. Just lubricate with a light machine oil when fitting and apply the usual torque figures...Ian
There are two different lengths used, depending on which part of the head, I think 1-3/4 and 1-7/16. I think 5 each, although maybe someone can confirm or correct me. Use the gasket to keep them in their correct places.