I just completed this conversion a couple of weeks ago.
It does make a huge difference in feel & I believe it stops better because you can apply more pressure than with a manual.
You can buy high performance brake linings that will improve your stopping distance too. I saw an ad for someone who specializes in performance drum brakes - but can't remember where. The point I'm trying to make is drums can be 'enhanced' to work much better.
That said - just adding the booster to your truck will make it a lot safer & more responsive to hard braking.
remember though that when drums get hot they fade - booster or not. So tell Mom not to ride the brake down hills or in town cuz once they get hot they don't stop as well. The same can be said for disks except they cool much quicker & are harder to get fade.
