I think that at the same calories, while on, you will be less likely to store fat. Steroids will make better use of food. I would continue to slowly push the cals up, and watch how your body responds. See what you can handle and keep pushing. If you see yourself getting fatter than you'd like, dial it back a little. Otherwise, push forward, keep the food clean, most of the time, and see what kind of new ground you can break, using Anavar!
You will probably find that you can handle more, than when you were clean, but once you come off, you may need to dial it back a little. Hard to say though. There is a good chance that the added muscle mass will require more cals to maintain. It's all going to come down to trial and error. Besides the mirror, I would use pics. It's easier to compare them to how you looked 2 wks ago