Extending our current ip range

Hello all. Ive had a look through similar topics but still hitting a few problems so was wondering if I could pick your lovely brains.

We basically have two vlans and are currently running out of IP addresses (well actually we have more machine/devices) on our curriculum network and we're planning to make sure we have enough for around 2000 machines.

Our curriculum subnet is 255.255.254.0/23 (class a) - 510 already maxed out.

Our admin subnet also 255.255.254.0/23 (class a).

Now im not sure if i understand this correctly, but considering we have two vlans to accomodate both networks (admi 10.64.90.xx range - curri 10.64.92.xx range) would there be problems if we just used a subnet of 255.255.248.0?

Sorry if this seems very n00bish. Any help appreciated. Ta!