10. Rear Bulkhead Top Rail
A double-hoop or "cobra" style roll bar requires additional strength and material along the top of the rear bulkhead. The custom design uses 1"x3" rectangular stock across the entire width of the bulkhead to meet the rollbar requirement. The ends simulate the book design while accomodating the larger cross rail. The design does add weight to the chassis, but the trade-off is worth the increased safety and unique styling. The oversized cross rail also provides additional strength and geometry for mounting seat belt brackets.
The 3" wide cross rail was notched and then filled with a 1" plate to simulate the 1"x1" tubing used throughout the book chassis.
A gusset plate was added to join with a triangulating member later in the build while closing the ends of the cross rail at the same time.
As the thickest piece of steel on the entire chassis, a 1/4" plate caps off the assembly to support the rear suspension mounts from below and the roll bars from above. A 3/4" square tube finishes off the back side as per the book design.