adding new hardware

I recently bought an extra HDD and DVD writer. I added them like this: (I'm not good at hardware, so I hope this is correct)

PRIMARY master: DVD writer /dev/hda
PRIMARY slave: DVD-ROM /dev/hdb
SECONDARY master: HDD 40GB /dev/hdc
SECONDARY slave: HDD 250GB /dev/hdd

(I'm not sure about the /dev/hd*, but it would make sense if it was this way.)

I set up my linux box with these settings:

PRIMARY master: HDD 40GB /dev/hda
PRIMARY slave: DVD-ROM /dev/hdb

So I was wondering if I change my grub.conf into this:

default 0
timeout 10

title=Gentoo Linux 2.6.12.5
root (hd2,0) # was (hd0,0)
kernel /kernel-genkernel-x86-2.6.12.5 root=/dev/ram0 init=/linuxrc ramdisk=8492 real_root=/dev/hdc3 #was real_root=/dev/hda3
initrd /initramfs-genkernel-x86-2.6.12.5

would this boot correctly?
I booted without changing the grub.conf and it did well till it couldn't find root (/). When I pointed it to /dev/hdc3, it loaded /, but it complained about the filesystem being dirty. I find it weird that it found the /boot partition (/dev/hda1), but failed to find the root (/dev/hda3)... so that's why I'm asking if the system would work with these changes.

Should I change any other file as well? /etc/fstab comes to mind, but are there others.

Thx in advance :)