Hey what's up guys...I have a question I own a '02 Silveardo with a Cat-Back Exhaust.. I want to put headers on my truck but I don't know which one's to get the shorties or long tubes.. They told me that long tubes give you more horse power... My truck is a 4x4 would it be a problem installing them if a got long tubes?? and also I already have a exhaust system would the headers just bolt on to the exhaust system like the factory ones??Thanks for the help..I appreciate it!