If you're running him as a lead, you probably want Hidden Power Fire over Rock, to cover the ever so annoying, Ferrothorn, Forretress, Scizor, And friends.
Forget speed Ev's, they really aren't usefull here.
Put the rest of those 252 Ev's in HP.
And I reccomend putting Stealth Rock on either Tyranitar or Swampert, so he can have brave bird, because he'll be completely screwed by taunters.
I guess he's good, I personally prefer Hammer Arm to Curse, With Avalanche benefitting from the speed drop. But what you have works. Fill out your Ev's.
What you've got works, I would suggest replacing Avalanche with with Stealth Rock, ( Part 2 to the Skarmory suggestion ).
255 Ev's in speed needs to go for 252, Use the extra 4 on Hp, Life orb as an Item, it works much better than Expert Belt.
Flamethrower over Heat Wave, the 5 power different isn't worth the 10 accuracy difference.
And Timid nature would work better here, The Life orb has most of your damage covered for you to be able to outspeed your opponent.
You gave him a Dragon Move, and Scarf chomp could easily take him down, And Scope Lens?
Nasty Plot over Dragon Pulse, And he can priority or non-Priority sweep, fairly well.
You have 3 pokemon who have 4X weaknesses, and to top it off, they're all different, You should really try to re-arrange your team in a way to avoid that, maybe cut some of them, such as Charizard.
You might want to have a Spinner on your Team if you keep Charizard, just a mental note there.
And Also, Most players on PO don't play by item clause, and it just looked like you were.. Well, Trying to.
Don't be afraid to throw on a Second leftovers onto that Tyranitar, And another Life orb on Lucario, Its a very rare occasion that PO players actually play by that.