Extreme, Elite, DISC, Mountaineer and Ulite all share the same spacing. 2.18" from front to rear sets. Height will depend on the scope you choose. The obj bell (mainly) but you will also want to pay attention to the ocular bell if its really large. Most are not huge but ive see a few. A large ocular might hit the bolt on a few scopes.
Medium should be ok on scopes upto 42mm objective. Possibly upto 44mm.
Height of mount from top of receiver to centerline of scope tube is – medium 1.13″, high 1.25″
Also pay attention to the scopes available mounting area. Since its a 1 piece design you need enough room for the eye relief of the scope.
Outside to outside of rings is 4.29″. Standard rings are .63″ wide