Hope you don't mind me reviving this thread. My '75 Plus 8 has the Rover 4 speed transmission and it is starting to be quite noisy in 3rd gear under load (louder when hot). Early in the New Year I plan to pull the engine/gearbox and investigate. If the gearbox is not repairable I would opt for a 5 speed replacement. I have read plenty on the T5, 380, LT77 as replacements but very little on user experiences with the Vitesse MX5 kit. I am not concerned about durability of the MX5 in my totally original Plus 8 as the 1975 model was actually the lowest powered Plus 8 ever turned out (still more than adequate). I am more concerned about whether the kit is truly a bolt-in or whether mods to cross members/transmission tunnel are needed. I know that the earlier Moss box front cross member and firewall would need extensive changes to accommodate the kit. Does anyone have any direct experience with installing the Vitesse kit in a Rover 4 speed Plus 8? Thanks.
