sagegreen said:so, that means, If I drive POS 2 the Box can change the gear within POS 2 back to POS1, in the case of lower speed for example. WEll, I never noticed that. the only thing was, if I stopped because of a traffic light, it was possible to drive with POS 2 again after the lights went green. but I think, that is possible to all Auto-boxes (?)
I hope the technical inside of the 387 is the same / close to the common boxes like the known pre-code boxes. I orderd a good used spare BW35, precode 303, yellow plate. It should be no problem to fit the 303 into the NADA car?
Rover boxes should be SECOND gear only in the "2" position, so if you come to a stop with the lever in that position, it will pull away again in SECOND, and stay there, with no shifts. This is different to all other BW35's in other applications where "2" gives you 1-2 & 2-1. With those you haven't got SECOND gear start, which Rover wanted to retain. A 303 will bolt straight in in place of your mystery 387. Even though it's bound to have been interfered with since new, I have to say I'd love to have a look inside that 387.....