Tilton makes a couple of 930 starters that have a different style motor/solenoid then the HiTorque models. They can be somewhat clocked but not 360 degs without some changes to the snout. They do sell blank un-finished snouts for your machining pleasure. These starters have the motor more inline with the center of the flange and have the solenoid hanging off the side. Below links to the pics/blue prints/ and info. They have 2 models one is std hp and other is hi-hp. The prints below are, I think for std hp version, not sure if the hi-hp is longer in the motor section. One other thing is that it looks like it could be clocked to almost any position since the solenoid assemble looks farther back then on the HiTorque models that have the motor assembly too close to the bolts that hold the snout to the bell housing.
Tilton Engineering - Starter, OE Replacement, Porsche http://www.tiltonracing.com/pdfs/4172.pdf http://www.tiltonracing.com/incs/ima...?picture=s0021
Summit Racing Parts and prices (Links might work)
TIL-54-11061 STD Ratings ($390 usd)
TIL-54-21061 High Power ($470 usd)
If your going to start with hacking up a starter I would look at this. One other thing is that it looks like a nicer fit but I'm spatially challenged and unless I had one in my hand hard to say.
HTH
Sandy