I've spent hundreds of hours investing my time into limiting ropes, excuse my comedy act...
I've had access to a lot of expensive equipment and put my complete line to 5500 lbs. My biggest competitor only made it to 340lbs. I did a lot of testing in the rig shop as far as mounts and fittings go. The welded eyebolt is the weakest. The U-bolt is the strongest. The SS eyenut is 2nd strongest. The products that I wanted to associate with my lines were far too expensive and would end up being close to $70 at wholesale pricing. As far as mounting to the pole and dash goes, A SS u-bolt that is 1/4-1/2" proved to hold up well. With each increase in imperial measurement, the load went up by roughly 10%. Ex. 1/4" = 2000lbs, 5/16" = 2200 lbs.
However, there must be a weak point in the system. If everything is strong, the dash or pole will crack. I stand by what I have advertised. None of you will break my limiting rope. Put your car under a crane and hook up the limiting rope, your car will be picked up no problem. Because the line is strong, its important to have weak mounts. The eyebolt is the weakest, but I run it. I would rather have that break then crack the dash of my 2011 ski.
Good setups:
KR Lines + Eyebolt = Balanced
Other lines + U bolt = Balanced
KR Lines + U bolt = Not balanced
Other Lines + Eyebolt = Not balanced
It just depends if you want a stronger line or stronger fittings. I dont mean to turn you away from others that make lines as well. Profound Dynamics and ATP make great setups and they are all complete if Im not mistaken.