I have a 1989 BMW 535i 3.5L. planning on dropping 1 to 1.5 inch. Possibly installing twin turbo custom setup after complete engine rebuild. Would love to get between 800-900 bhp. Have heard you can get 1000 bhp out of these engines. But I want it to be quite until I get on the peddle. Going to give a complete interior redo with custom fiberglass panels.