Why so high on the test for a first cycle? You'll put on a shit load of weight, but then you body WILL return itself to as close as possible to your pre-gear weight (homeostasis). I don't know about you, but If I eat off cycle like I do on cycle, I look lke the marshmallow man from Ghostbusters....and that how you'd need to eat to retain your new found muscle.
Do yourself a favor and drop it down to 500 and save the deca for the next one. I think everyone here can agree that the reason we take gear is to build from one cycle to the next, and your setting the bar awfully high with 750 as a first cycle.