Concerning pinion angle if you can post some pictures of what you're looking at.. this is my opinion only.. on a street driven car you need enough downward pinion angle to get a good rotation on the needle bearings.. and ideally you want it to come two as close to straight as possible at wide open throttle.. if you could get the GoPro down there on a pass and see how much movement you have.. you could tune for that movement.. some people feel there's a magic number but I think every car will need something a little different.. because of weight and horsepower.. this is what I have found worked on my car