MTU values are from 1500 to 9198 bytes.
Don't have a 4848 to test with but according to this document, there is no "ip mtu" command. It is just "mtu <size>" for physical interfaces as well as SVIs. The values are the same for both SVI and physical interfaces.
Thank you for your answer.
I tried to configure 4948 myself.
The interface with IP configured is IP MTU applied.
I was able to configure the 68-1500 MTU.