The fact that you don't know the answer to that question is concerning. Tren isn't even close to deca, as far as potency, results and side effects. Kind of like saying beer and Everclear are both alcohol, so why not just use Everclear. Spend some time doing some serious research, especially before you use it.
You really should be using either one for this run. Everyone has said to keep it simple and basically run a test only cycle. It's the smart move and you'll accomplish what you want with the proper diet and with a ton less potential side effects (which you're not prepared for with your experience). Good luck.