For those who are curious
I just heard back from Nathan at CBI, who has been super helpful and informative by the way.
Apparently the mounting is very different for the way they mount the Tacoma Bumper. I guess i would need to fabricate mounts that fit the 4Runner, and then fit the bumper onto my own mounts. He said that frame holes are located differently too.
I am a little confused by this, since guys are bolting up Taco ARBs with the same holes (Is that right?) I guess I was just assuming that I would have to shorten the frame to fit into the Tacoma mounts, since all the info I have seen says the 4Runner frame is just longer than the Taco, but holes for tow hooks etc, are still basically the same.
Pics of the CBI mounts would help I think.