Hedman Headers Won't Fit
I wrestled with my set for a long time to get them in there and it took a lot of work. The engine has been out twice since then and every time the headers stay in. This may sound a little dumb but if you can easily pull the motor out I would just do that and put the headers in then drop the engine back in. If your only doing a header swap it may not be worth it.
Good luck and watch where you throw your wrenches.