Are you sure about using trickscarf Gengar? If you like trick, consider specs for power. If you don't find it necessary, consider SubSplit. The only reason I can see for using it as it is now would be revenge killing DD gyara and DD mence at +1, but switching Gyara to bulky DD should take care of that most of the time. Other than that, the team is very solid. Porygon2 is somewhat rare to change something just for him, and a Loom that has set up has no problem with either Heatran or Porygon, and Gyara also rapes Scarftran since you have chosen Jolly (the right choice).
DDmence/gyara were exactly the reason for scarfgar, theay totaly killed my team (though it wassnt the same team, 2-3 pokemon changes since then). And yes, i fought against ~2 Porys in the last month.