headers

Hi everyone, I've been trying to find a dual muffler header system for my gen 3 but nothing comes up from a reputable company. Has anyone tried these from ebay? They seem to have the O2 sensor inserts already built into them, but I'm worried about fitment Link 1 Link 2

Hello guys hope you're good, there are some udpates after i modded my stock header to 4-2-1. Before, i just modded the diameter of the end pipe (60mm). Now, i modded the secondary tubes to 50 mm but i did not mod the primary tubes they are Still stock size (38mm) should i mod them too ?

Hello all, hope you're good. I modded my stock header to 4-2-1 i wanna ask if a 51mm end pipe will work good ? Or should i do 61mm end pipe ? I have 2 exhausts that i wanna experiment (akrapovic or the yoshimura ovalcone) wish one will work the best ? (Gen2)

What is the pipe size for slip on that work with the gen 2 yoshimura headers and mid pipe??

Has anyone tried them or heard of them? I want to go with Coffman dual slipons but don't know what header I want to do. http://www.blackwidowexhausts.co.uk/gsx1300r-gsx-1300-r-hayabusa-2008---2015-4-2-downpipes-collector-de-cat-1770-p.asp