As Larry says, typically the RUM's and WSM's have a different shank size than other calibers. Other than that, they should all fit.
It is common for savaholics to get a stevens action for the basis of a custom, as the actions are typically the same as Savages.
The other concern is the bolt head - 0.378 for the .223/.204; 0.473 for pretty much everything else smaller than a magnum. Like the barrels, these are pretty much user changeable.
JC