would an exhasut cutout kill my engines performance. i know back pressure is an issue, but i was wondering if anybody had don't it on bassically a stock K-5. i have a new GM crate 350 and new headers. i drive: 1986 Jimmy 4X4 brown and tan new 350 engine no rust 31 inch tires re-wired taillights (myself) i have bad vibrations!!!!!