First, startup scripts generally only accept 'stop' or 'start' as their only parameter. This is passed by the startup routine as it launches each startup/shutdown script.
The chkconfig, basically puts a symbolic link into the startup directory such that the startup/shutdown routines will look at it.
Thus you cannot pass parameters using this process.
-----preferred method 1
However, the way usually used to setup variable and parameters is to put the parameters into /etc/sysconfig/.
The script usually imports these configuration parameters early on in the execution of the service startup script (via a . /etc/sysconfig/).
---- not perferred method 2
You can edit the startup script that is usually located in /etc/init.d/ to do what you want. The problem with this approach is that if you happen to apply an update it is likely that any changes like this would disappear.