Well like I said call and ask gm about the specifics of the warranty. I am pretty sure my buddy told me he had to have it installed at a dealer for the warranty to be honored. He may have been told wrong and I have never looked into it so check it out for yourself. They do alright in a gbody. I do not know what his monte runs, I don't think he ever took it to the track but he has a holley street dominator for the intake, an edelbrock 600cfm carb and a set of headers with true duals, no cats. It isn't a power house but it runs out ok. My lt1 firebird is in the 13's. I have raced him several times and I would guess he is probably high 14's.