I had headers only once on one truck,they quickly rotted away,and I wasn't sad to see them go--put regular stock manifolds back on instead...noticed very little difference in performance,and was tired of them always "ticking" at the heads,blowing out the gaskets there,and at the collectors...............................................................................................one thing I did that helped prolong the collector gaskets life span,was to put a tight fitting muffler adapter inside the collector and the header ,so the hot gases wouldn't be able to get at the flange as much where the gasket goes--it made a big difference,having a "sleeve" inside to route the hot exhaust away from there....the flanges warp easily too,most are too thin...I had to use double gaskets to get a seal on my warped collectors...
