We have one subnet 172.27.68.1 255.255.252.0, our distribution switch is 6509. WE want to do some basic VLANS without screwing up routing and changing subnets. The 6509 has 2 48 port 10/100 ethernet ...

I'm not immediately aware of any sort of limitation in the 4000 switch since all you should need to do to set up the inter-VLAN routing with the 5500 switch is establish a VLAN trunk (ISL or 802.1Q) ...