There are several good builders to deal with.I am fortunate to have a builder that has become a good friend.I prefer dealing face to face VS shipping out to a distant shop.There are many special parts or more severe duty parts required for the trans to live in an extreame application.My junk with only 10 lbs of boost has more than 850 ft lbs of torque @ 4900 RPM.That would test the entire drivetrain:burnout: