Was it the KBIT or the KBIT-2 he took? AFAICT, one issue with the KBIT is that it's an old test (normed in 1990); the KBIT-2 was normed in 2004. So there should be a smaller spread in scores between the KBIT-2 and the WISC-IV than between the original KBIT and the WISC-IV. (http://www.ecasd.k12.wi.us/student_services/assessments/KBIT-2.pdf says 1-3 points, which is consistent with the 4 points your tester's seen.)

The CogAt is timed for 3rd grade and up - it looks like he ran out of time, or didn't attempt questions he wasn't sure of?

Is your district's G&T program really good, or your DS really unhappy in his current placement, that it's important that he be in the program? Our program is sort of lacking - it got called out in the district's last operational audit as a pointless waste of time and resources. wink OTOH, the school has been very good about looking at each kid as a whole kid, regardless of test scores or identification. If you can get what your kid needs without testing, I personally would not do a third test.