I'd retest.
Last spring the school did the CCAT (the Canadian name for the CoGat) for DS for entrance into a gifted program and at the same time we did the WISC privately to follow up on some LD related issues. DS's scores were way lower on the CCAT than they were on the WISC. The WISC matches our experience and gut feel for him.
I don't have studies to back this up but I have heard that the CCAT was not the best for kids with lower processing speed and/or 2E kids so I wasn't shocked but there was another kid in the same situation that is more evenly gifted and not 2E and his CCAT scores were way lower as well. Luckily the program allowed them to use their WISC scores to qualify.
