Up in the main menu across the top(Main, classified, forum) there is a FAQ section. The 3rd gen (4.4) actions came around in about 2005.
"Officially" the WSM's are all that spacing, but there are several members here who have them on the small shank actions. I have never done anything with my large shank, so don't honestly know which spacing it is. But it is a hazzard of Savage, there are always some interesting unofficial things that surface.