I tried searching but unfortunately can't find a dayum thing.
My car is in the shop right now and I just called them to see how the progress was going on the install. I had them install my headers (Greddy). To my suprise he told me that they couldn't install them because the downpipe (stock) wouldn't fit. Any body know the size of the Greddy headers so I can go out and buy the piping? Quick replies please, need a lot of help fast!

Well assuming you are having the correct Greddy header installed all he should have to do is cut the downpipe and weld on a flange because the Greddy header hangs about 6 or so inches lower then the stock. But if your mechanic can't figure that one out then I'd take it to someone else, possibly someone with half a brain or more. The pipe is mild steel, so if you had access to a MIG welder and a flange it'd save you about $150 or whatever he's charging. On a side note, when I put mine in my welder was stashed away with all my other stuff because we were moving, so I paid a shop to install. Luckily I did the motor mounts soon after because I found that the collector was rubbing against the stock header mount, the idiot who installed it didn't take the 5 minutes neccesary to grind it down while he was there. There is a very particular reason why I never take a car to a shop.

P.S. remember to wipe down all the stainless steel on the header with acetone, otherwise the oils from your finger prints will burn in and stain the header.