I apologize for not posting a more intelligent answer. Unless your car is known to have grounding issues, grounding kits are a load of crap, replacing your factory grounds will give you the same or even better results.
I read a review that a mag did a while back when grounding kits first started to come out... they dyno’d a car before and after, they noted a 2hp decrease with the grounding kit. After moving the wires around they got a 1hp increase but it took 6 different attempts to get it to not decrease power.
Based on the size of the box I'd guess it's around 1/2F, hardly enough to make much of a noticeable difference. Going with a 1F or even 2F then you may be able to notice a difference. But again it's not worth it unless you run a battery relocation or a super small battery.
Originally Posted by Kai
The wire will still ground through the bolt.
the reason I pointed this out is because a ground has to be secure, metal to metal contact. With the rubber grommet in there it can wiggle/turn and cause intermittent contact which will induce noise. It probably will not cause any problems when everything is new, but give it 6 months.
Illegal B16 - grounding the fuel rail can help, but it may not.
I've been doing some checking since I've been working on several different cars lately, and I measured as much as 15ohms between the ground terminal and the rail on a friend's stock EX, but I also measured .1ohms on mine and a beat-up DX.
It really does come down to the quality of the factory grounds, I'm pretty sure that if I would have slightly turned the nuts that mount the rail on the EX, it would have dropped the resistance... but it can't hurt to add a wire just in case.