I'm sorry but the part Wisner lists is specified for pre-64 94's. the Centenial you have is a later version. Also rangr44 is has a stamped sheet metal carrier. Whether the carrier Wisners makes for the pre64 model will fit is doubtful but be certain to ask before ordering. Quoting their explanation of the matter--
'These post-64 models were made totally different internally, using completely different parts, with about 95% non interchangeability with the earlier post-64 versions. ' and 'About all the parts that come to mind that do or can be made to interchange from the post-64 to the pre-64s are the magazine tube for the 20' carbine, magazine spring, magazine follower, rear barrel band & screw for the carbine, & the tang screw.' There's a lot of difference here so be sure to ask specifically before ordering. As to replacing cast followers with cast followers yep..usually a drop in as these are direct replacement parts..