Ok come spring time i'm looking to install some headers and other mods on my 2004 grand prix gtp and my question is how long do you guys think it might take? there will probably be 2 or 3 people working on it at a time depending if people will get in the way. I'm thinking around 11 hours or so maybe? also any input on what are good headers to put on it would be great.i'm looking for cheap but good quality maybe around 300 or so.