I had my starter box before I got my buggy but only use it on my buggy right now. Got a very good deal and new I was getting a buggy so I picked it up. Yes when I got my Hyper 8 pro kit I took the rear diff apart cleaned and put 1K in it. Then after a couple of gallons I took the middle diff apart and put 5K in it. So now I have 3k front 5K middle and 1K rear. Have not run it since I switched to 5K in the middle. As far as glow plug all depends on what temperatures your engine is running and how it is running. If it is getting up to at least 220 degrees and running fine I would not worry.