Here it is out of the Rule book. Except the 11.99 is now 11.49. The only way you could get away with out rear bars going to the bed is to have a funny car style cage in the truck. I've seen many trucks go with a soft cover to make the rear bars work.
From NHRA RULE BOOK
Mandatory in all cars running 11.99 or quicker, or per Class
Requirements. All roll bars must be within 6 inches of the rear or
side of the driver's head, extend in height at least 3 inches above
the driver's helmet with driver in normal driving position, and be at
least as wide as the driver's shoulders or within 1 inch of the
driver's door. Roll bar must be adequately supported or crossbraced to prevent forward or lateral collapse. Rear braces must be of the same diameter and wall thickness as the roll bar and intersect with the roll bar at a point not more than 5 inches from the top of the roll bar. Sidebar must be included on driver's side and must pass the driver at a point midway between the shoulder and elbow. Swing-out sidebar permitted. All roll bars must have in their construction a cross bar for seat bracing and as the shoulder harness attachment point; cross bar must be installed no more than 4 inches below, and not above, the driver's shoulders or to side bar. All vehicles with OEM frame (i.e., pickup truck where body bolts to framerails) must have roll bar welded or bolted to frame. Installation of frame connectors on unibody cars does not constitute a frame; therefore, it is not necessary to have the roll bar attached to the frame. Unibody cars with stock floor and firewall (wheeltubs permitted) may attach roll bar with 6-inch x 6-inch x .125-inch steel plates on top and bottom of floor bolted together with at least four 3/8-inch bolts and nuts, or weld main hoop to rocker sill area with .125-inch reinforcing plates, with plates welded completely. All 4130 chrome moly tube welding must be done by approved TIG heliarc process; mild steel welding must be done by approved MIG wire feed or approved TIG heliarc process. Welding must be free of slag and porosity. Any grinding of welds prohibited. See illustration. Roll bar must be padded anywhere driver's helmet
may contact it while in driving position. Adequate padding must
have minimum 1/4-inch compression or meet SFI Spec 45.1.