My XF Falcon doesnt pull up as good as I would like it to. It has the drum brake rear end, and has new pads at the front, and has had a recent brake fluid change. I would like to know some of my options to make it stop a little bit better (it's still safe, you've just gotta stand on the pedal really hard) How much difference would going to 4 wheel disc brakes make? I have a set sitting there but they would need a new caliper and new pads, and I'm not sure if they will fit my diff, (although after checking out this other diff I would like to use it because it's an LSD) What problems could cause it to be a bit hard to stop? what should I be checking? It's not the brake booster because it passed the test in the factory manual. Any other ideas on how to check out my brake system, and possible upgrades? could I get better pads or rotors? I am on a budget though which doesnt help. I have bendix advance pads on the front at the moment.

Cheers, Gab

get new rotors if ya old ones are worn.
yes i think discs at the rear help with xf's, but it can make it a bit harder to spin the wheels, although mine was a manual, so i never had a problem.

I'd be finding out what the actual problem is first. It would be a shame to go to all the trouble and expense to fit the disc brake rear to find the brakes are still crap.
My '88 ute has a drum rear but has a nice firm pedal and stops really well so you definitely have a problem there somewhere.
It could be a number of things, if you have reached the limit of your knowledge it may actually save money in the long run to take it to a trusted mechanic or brake specialist and get it fixed right the 1st time.
Your master cylinder could be stuffed and need an overhaul or replacing. Your rear wheel cylinders could be leaking and soaking the linings making the drums innefective. Did you get your front discs machined when you replaced the pads? They could be glazed from overheating and not allowing the pads to bite properly.
The brakes on my last car were very ordinary so I spent big $$$ on new slotted rotors and high end pads all round for it to be just as crap after I fitted them. I learnt my lesson there big time. Turned out the master cylinder was cactus.
Get the brakes working properly first and from there the lsd and disc brake rear would be a good upgrade if you decide to go ahead with it.
Good luck.