Hey there, I've searched and couldn't really find an answer to my question. I have a catback exhaust with a 2.5" pipe. I also have an ebay header with a down pipe that's 1.75" ... I was just wondering on a car with a few bolt ons, but no turbo, etc.. would upgrading the down pipe to be 2.5" as well would that make a huge or big difference? Worth the work? Thanks!