[EricH]

Looks almost like the one 330 did for the 2006 season...we moved the end rails farther in. For 2005 and 2007, we had three rails for mounting purposes on the inside.

Some pros and cons of the design:
Pros:
--clearly defined "keep out" zone due to the double rail
--strong
--simple

Cons:
--weight (those top bars add a lot--if you can remove them, do so.)
--Welding is virtually required.
--As drawn, the frame could bend if it takes a side hit. Consider adding inner blocks where the wheels won't go. (Which will also render the top bar mostly unnecessary.)