A couple of excerpts from online NHRA stuff.
If the cell is plastic it must be covered with metal if outside the vehicle. ie: hanging down. Why not just use a metal fuel cell? That is legal.
You need a steel metal frame work made from 1 1/4" DOM steel if the tank is outside the "frame rails". Why not keep it inside the frame rails?
No you are not interpreting this right, You can use braided line the whole way just not your nonstandard ie: not approved by NHRA stuff.
It's really quite simple. If it does not look safe and close to what everyone else is doing you will get a finger wag. jmo
Tanks: When permitted by class regulations, fuel tanks located
outside body and/or frame must be enclosed in a steel tube frame
constructed of minimum 1 1/4-inch O.D. x .058 chromoly or .118
mild steel tubing. All fuel tanks must be isolated from the driver’s
compartment by a firewall, completely sealed to prevent any fuel
from entering the driver’s compartment. All fuel tanks must have a
pressure cap and be vented outside of body. A positive-locking
screw-on fuel tank cap is mandatory on all open-bodied cars.
Insulated fuel tanks prohibited. When used, fuel cells must have a
metal box protecting the part of the fuel cell that is outside of body
lines or trunk floor, excluding hose connection area in rear. Nonmetallic
fuel cells or tanks must be grounded to frame.
Lines: All non-OEM fuel lines (including gauge and/or data
recorder lines) must be metallic, steel braided, or NHRA-accepted
“woven or woven-pushlock.” A maximum of 12 inches total (front to
rear) of non-metallic or non-steel braided hose is permitted for
connection purposes only; individual injector nozzle and motorcycle
fuel lines are excluded. Fuel lines (except steel braided lines) in the
flywheel/bellhousing area must be enclosed in a 16-inch length of
steel tubing, 1/8-inch-minimum wall thickness, securely mounted as
a protection against fuel-line rupture. Fuel lines may not be routed
in the driveshaft tunnel. It is mandatory that fuel lines passing
supercharger drive belts be steel braided, NHRA-accepted woven
or woven-pushlock, or be enclosed in protective steel tubing. A
current list of NHRA-accepted woven or woven-pushlock fuel lines
is available on NHRA.com. All NHRA-accepted fuel lines must use
ends that are specifically designed for the type of fuel line being
used. No hose clamps allowed on NHRA-accepted fuel lines.