Hi Matthias,
Maybe Larry, Ron, Rocky or others have a few suggestions. The studs to me were not the issue... Just not enough clearance to get through header pipes, no room to down between frame, and certainly can't go up... I assume you are replacing with a stock size starter?...Not sure exactly where you live, but might think how you can get a DB starter and take the old one apart in place. If you want a stock starter probably have to lift up engine, if headers are not a drop option?? Again, maybe others have a few suggestions for you...sorry. Ron