pdp-11/24 backplane unique ?

hello ! I got two pdp-11/24, one for 110 Volts and one for 220 Volts circuits. I live in an area with 220V circuits, so it would be much easier for me to use the one driven by 220V. unfortunately all the interesting cards are in the 110V version. now my question is: can I exchange any card between the two pdps or do I also have to exchange the backplanes ? thanks for help, Andreas -- ********************************************************* * Andreas Mueller * * * * Multi-Media-Labor || Uni-Tuebingen * * phone: +49 7071-2978567 or +49 7071-2977821 * *********************************************************