One way to approach this might be to ask them if they could provide a 'gifted cluster'. This is the terminology my son's public school used to do exactly what you want. While the official line was there was no testing or GATE till 4th grade. They did attempt to cluster the top kids so they would have peers and teachers who broke kids into small groups.
Yes. This is the real request _I_ want to make. But how to make it sound okay?
I'm afraid the term "gifted cluster" will be off putting. This is not a school really excited about it's gifted offerings...
