3.91 or 4.10

Hello Everyone,
I have been running 3.73 with a gv unit and I would like to see more gear. I have been contemplating 3.91 or 4.10. I am using 295 50 15. The motor is a stroked 340 that dynoed 540 hp and 540 tq. The tranny is a 904 with low gear set. This is a street only car.

My other question is about pinion angle. Will a wrong pinion angle cause a loss of hp? I ask cause I had a vibration on acceleration, so I reset the pinion angle and it feels like I added 50 hp to the car.

Thanks for all the great advise that I have gleaned from this site.
Author: admin