Kristian,
See previous thread with photo's; there's a bit more to it than simply flipping the ring gear, but all parts available.
The ZF case is ribbed and stronger, plus you'd get the CV axle output shafts and the M1 has oil cooling if you retain the rear cover.
http://pantera.infopop.cc/eve/...0045562/m/4981072156
With your application and the fact you are using a dry sump, you could investigate retaining it in the current orientation and lowering the motor for an overall lower center of gravity?
Julian
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