My bad I misread the coil bit I read it the other way round as it ballest coil into Sierra hence why I said either will work, the Sierras I have experience with are 12V ignition systems anyway, what I meant was 9V coil which can give same output as 12V so it saves energy.

An interesting read, the Rover V8 also came with the Borg Warner 35 this may be worth considering, this is why the P6 originally was auto as they diden't have a manual box avaliable to take the torque. They eventually strengthened the Rover 2000 box.

Martin