Those are great scores and plenty to get into whatever school you are looking at for kindergarten/1st grade. I agree with Puffin that further testing likely won't tell you much, if anything, more.

Instead, consider waiting until he is 6 to test with the WISC IV or SB-5. My DS took the WISC and they do have extended norms for when kids hit the ceiling on subtests. Good luck!

Mom to DS9 and DD6