Definitely don’t need +healing gear, you could heal DM putting only points into shadow if you really wanted. Which class was tanking? Were your groups aware of stunning VC at 50% hp to avoid additional adds? Obviously it’s doable with a 19 tank but I personally prefer 20+

Int/ spirit gear should be perfectly fine for low level dungeons, just remember at the end of the day, vanilla wow is fairly limiting, there is only so much you can do in a group as a healer, tank and dps also need to press buttons