when rover launched the 1275cc coopers the engine was moved forward about an inch to give more clearance for the carb around the bulkhead. this maybe worth considering ???
also, didn't the rear subframe for the injection models have different exhaust mounts ????
Whoops forgot the rear sub exhaust mounts - can be chopped off or left if unnecessary - the "conventional" exhaust mount holes are there on genuine frames - can't speak for aftermarket ones.....