You may want to read my past post on this topic... Is went though a lot of BS, three starters and and broken flywheel teeth before getting mine "right". After a lot of research, a new flywheel and .....and new starter from Rob at robbmc startery, I am good and my car fires up as it should (I only run 10.5 compression but they OEM starter was straining to say the least).
Call Robb - he was one of the first folks that really helped me out and the only one who was consistently recommended....hope this helps.
RobbMc Performance Products - RobbMc Mini-Starters