Tom,
Have a look at my build thread or go here:
IMI Performance Products, Inc. Hi Torque
I think I created a thread about 930 starters about a year ago. After trying a lot of stuff I got a Hi Torque starter that is spaced out for sand rails. Tell them you want the sand rail version with about a 1.5" nose spacer. Fits well, clockable, and the only one I found that would work. About $250.
This will put the engine far forward and lines the uprights and output shafts up (at least on a 930 it does). It just fits with the half shaft held up and I think the bolt heads will clear too. I have not put all this in the car but that is coming here soon as I have the clutch stuff now and racing season ends this weekend.
Ron