i just purchased a bullydog gt tuner for my 03 duramax. i purchased this because i heard some good feedback and because my buddy gave me his oil power pup for a refund for half the price for a new one. whats the word on the gt tuner? any good for my truck? im still just learning about diesels too and having a very hard time. trying to find some small cheaper performance products for my truck. i installed a K&N filter on it not to long ago and i installed a custom made 6" single chrome stack on the back. the stack isnt quite finished without some smoke coming out. i get a tiny bit at high rpm but thats it. any other products or changes i can make to my truck to get that?