there's gonna be a clever wat redhat can do it for you i expect, but if there is, all it will acutally do is.....
change to /etc/init.d/rcX.d where X is the runlevel you use 3 = text 5 = X login. run an "ls" and you'll see lots of things like S80sendmail. the S means Start, and the number between 0 and 99 is it's position. just change that part of the file name and it will be loaded in that order.