On my precision rifle I locktite both, 'cus I want everything to stay put and don't expect to be swapping these items around.
FWIW, I level the scope to the action, using "string levels" from the hardware store (I like the alum. Stanleys and clip the string holder off) then after I have screws down snug and KNOW scope is level with action, I replace and locktite them one at a time and tighten them down.
Mike
PS - my gunsmith doesn't do this but then he swaps his scopes to customer rifles all the time to assure himself that his work is good and then has the customer install his own scope, or charges to do it for them if they provide their own scope. In this case he uses the locktite. (NOTE: always use the proper hex head or proper fitting screw driver blade width to prevent damage to screws that have been locktite'd down, should the time come you need to make a change)