Hey guys, I think next month I'm going to be adding some bbk equal-length shorties, bbk o/r h-pipe, and a mac catback, and maybe a set of the march power + amp series underdrive pullies. About how much will these mods add up to for a RWHP gain, and will it be noticable? If I have clogged cats now, will the new o/r h-pipe give me an even bigger power increase?