Also how is the diet looking. What calories are you hitting and what is your Macro split?
But thats why i say both those compounds aromatize heavily, reason i suggested an AI so you know that your gains are more clean then water weight so to speak. So maybe something like aromasin, arimidex or letro to control estrogen and water weight.
Another option would be to lower the dose or drop the deca and dbol, I'm sure he doesn't need all that at 87 kg 17%bf..!!