What is this bracket on a 6.0?

I just realized this bracket is not installed on my 6.0 when I was browsing magnachargers instructions (where the pic is from). Its laying in the back of my DD, I guess It fell off while transporting it. Is is needed. Its an 02 lq4. Thanks

That is a fuel rail stop bracket, goes on the rear of the driver side head.

I got the motor in and running fine. Been driving it a little bit. Do I need to put it on?

Its a real pain in the ass to put on with the engine and/or head already installed in the vehicle....i'm pretty sure it won't hurt anything to leave it off...i can't really see anything bad that could happen without it, but i won't swear to it.

its supposed to shut off the fuel in case of a wreck or something like that........ so dont get i a wreck