Hello, this is a pretty solid team here.
Some first off things to nitpick are
Lava Plume on Heatran to status Pokemon with burns as they switch in.
Toxic is also a great option as with that you can easily status an entire team. You can easily check Latios and Latias with ease, and with Gastrodon absorbing Surfs fired at Heatran, these two perform very well together by crippling entire teams in the process.
Now you should also consider
Scarf Landorus over Flygon. Not only can he more reliably check Dragon Dance Salamence thanks to it's boost in speed, it also still has the same ground and electric immunity, with higher speed and attacking stats. The only withdraw is having a fuller effect to Stealth Rock, but that shouldn't bother you too much. It also still has access to the great momentum move U-Turn that greatly aids in shuffling up teams through switches with your hazards down. Now, just as a preferance, I like using
Forretress over Scolipede due to it's access to Rapid Spin and Volt Switch, but because you want to really use Scolipede, I will leave it up to you. The biggest benefit is making you much less weak to the likes of Terrakion and Mamoswine, and the fact Toxic Spikes are not very good in the current metagame.
Good luck!