The inside of the headers require grinding to make the accelerators fit. They just don't drop in as noted in the thread above. A die grinder is pretty much required unless you have several hours to do it with a 1,500 rpm drill and by hand. I used a 6 amp, 15k rpm grinder with a 1/4" shaft, which is a handy tool to have. Finished with another die grinder using a 1/8" shaft and 60 grit sanding flap wheels for final smoothing of the inside. The 1/4" & 1/8" die grinder set from Harbor Freight are VERY useful tools to have. After install, the accelerators move the headers forward, so you have to move your exhaust forward also. Photo included to show what I mean.
