Barry (68F250) just forward these pics to me...thanks Barry! These show the factory front sway bar...the kind which spans the area between the radius arms behind the front axle area, instead of mounting in front off the I-beams like most aftermarket kits are. However, very few of the Camper Specials from our era got one of these, and Barry told me that he thought only the 1-ton Camper Specials (F350s) would have had one of these installed from the factory, but he wasn't 100% sure. He said he's seen them mounted a lot on a lot of post-'72 Supercabs.
In the following pic, you can also see that the radius arms are much beefier than the standard pieces, and the holes drilled for the swaybar are slotted.
Because these swaybars mount behind the front axle area, they would interfere with header installation, but if your truck doesn't have one of these, you'll be OK.
...and as Ford_Doctor mentioned, the tank interference issue was on trucks equipped with the 25-gallon in-frame auxiliary fuel tank. Since there wasn't room for the left-side exhaust pipe, you couldn't run dual exhaust unless you ran both pipes down the passenger side....or ran the left-side pipe outside the frame. The '67 F250 Camper Special I just bought had this setup. It would seem to work well, except that you'd have to run wheels with a greater offset, for additional clearance for the pipe between the tire/wheel and the rear springs...unless you had the pipe exit before the rear axle. Take a look at the pics I took of this exhaust setup:
http://www.fordification.com/images/67- ... tion02.jpg