You need to speak to Doug Anderson. He can answer any questions you have. He is on vacation all this week though. He will be back next Monday. I went up there about 3 weeks ago just to meet him and bs awhile and he started digging out parts and showing me the "new" cam bearings that they use (they are bad ass) and some other cool stuff. They know how to build engines and they have been doing it a long time. Some people may have had problems with some of their motors, but any engine builder, I don't care who it is, if he builds enough of them, will have some come back for one reason or another. Just rember who ever you chose to build a motor, this is not a run of the mill motor. Spun bearings, or what ever else not necessarily falls back on a bad engine builder. If a car has a waste gate set up that habitually Overboost and causes detonation is not a builders fault. Running a car too lean isn't either. Many things can contribute to spun bearings, bearing falure ect. Simple fact is clearance is the key to these motors living. After that, its the tune of the motor to keep it happy. Anytime you push a motor to the limits of safe whether it be with leaning it out, upping the boost, or too many revs there is a chance something "bad" will happen, so just because a "guru" builds an engine doesn't mean its bullet proof. Grooms is a little expensive, but the compensation is turn around time. They have thier stage 1,2,and 3 motors in stock. You send your core and recieve a fresh motor with no wait. And a warranty.