Change Max Chars/SMS using HTTP SMSC With Kannel 1.4.1

Hi List,
Which file should be patched to be able to handle MT with more than 160
chars without concatenate it? In the other word I want to do a MT in 1
time push. I have checked sms.h and edited the #define SMS_7BIT_MAX_LEN
500 but it doesn't work. Many thanks for your kind replies and helps.

Regards,
        
        
Willy