I just installed eBay headers into a Kooks dual cat Y-pipe. Excellent fit only minor mod. The headers even allow better access than the factory manifolds.also excellent found clearance. These are the headers with the O2 bungs on the outside of the collector.i did have to shorten the driver side collectors little bit to line up with the Kooks Y-pipe. Other than that, quite uneventful. I did remove the starter and the oil filter but did not touch the steering linkage.