hey guys, i have the 2500hd and im lookin for some longtubes, i've been looking online on ebay and stuff and have found the OBX and some by DNA Motoring, they both look identical but they say they are only for the 1500's... so i'm wondering what is the diff. on my 2500? or is there one? i know i'll have to have the pipes from the headers to the muffler made which isn't a problem but i just wanna find a set of headers... also those OBX ones and DNA Motoring ones both have a 2.5" collector, is that ok? my factory pipes are 3" so im just wonderin...