Do I need exhaust on my drag car?
 

I have an 84 GT that is set up for drag only. Will I gain anything by adding an x-pipe and racing mufflers. I have heard open exhaust is best, but I also heard that the exhaust needs some back pressure and will gain hp if I have some sort of mufflers on it. Any advice on which way to go. The engine is a 351w and makes 450 horses at the flywheel. Not to mention my neighbor would like some exhaust on it.

Yes, I would put some sort of muffler on it. Lots of tracks and racing organizations require the use of a muffler. Don't go with an X-pipe on a drag car. To get the most out of your combo run a straight through muffler like a Bullet Muffler like i have on my car. To get the most hp out of a dragcar with exhaust..find out where the exhaust is the whitest and cut it off there. I have 5" dynomax bullets on mine and i actually picked up a few mph with the mufflers over open exhaust. Plus open exhaust gets annoying after awhile.

What do you mean by where it is the whitest?