Hello. Years ago i bought 300hp crate motor and it had a oil leak. The warr. said any chevy dealer across the nation could work on it. Do you have a chevy dealer near you to take it to. That will eliminate the middle man (your installer). I had to take mine back 4 times at no cost to me. Gm is jerking you around so maybe you will get better help from a dealer with a good service dept. and let them work with gm's BS.