Good team, but it could do with some changes, and some of them have already been proposed.
First of all, definitely change Payback with Ice Punch. Payback is not hitting anything that Ice Punch can't, period. Jellicent walls you in TR anyway, and Gengar dies from Ice Punch after SR (82.06 - 96.94%), so you don't really need it. Ice Punch murders Giscor, D-Nite, Landorus-T, and some more, so it is very useful.
Also change Donphan, as the one you have doesn't do a lot of your team, as said by others. Imo, you need a poke that can deal with Jellicent which is problematic for your team, as it has Taunt to prevent TR, and walls most of your team. Celebi and Magnezone are both good options. Celebi has good bulk, helps with Jellicent and Politoed, has Recover to stick around, and can set-up SR, which your team lacks, and TR, while also being able to U-turn to bring one of your teammates in safely. Here is the set i am talking about:
Celebi @ Leftovers
EVs: 252 HP / 4 Def / 252 SpD
Trait: Natural Cure
- Giga Drain
- Trick Room
- Stealth Rock / U-turn
Magnezone on the other hand also helps you with Jellicent, as a Modest LO Tbolt ohkoes after SR, while also trapping Skarmory, which is mentioned as a threat. Finally Zone is a good TR abuser, as it has low Speed an hits like a truck. Here is the moveset:
Magnezone @ Life Orb
EVs: 252 HP / 4 Def / 252 SpA
Trait: Magnet Pull
- HP Ice
- Flash Cannon
- Volt Switch
If you think that you have Jellicent covered then you can opt for the ScarfMence set that Sciztar has proposed, which gives you a win condition after you weaken the opponent's team, and also gives you a poke with real speed, that can revenge kill pokes outside of TR.
Finally about the Heatran set. I would definitely put LO instead of Specs, as you want to abuse the TR turns, not get forced out by resists/immunities. Also put Fire Blast instead of Overheat, you want to abuse the 3 turns of TR, not kill your SpA every time you fire your STAB move. And finally if you don't go for Celebi with SR, then definitely put it over HP Grass, as it is a must for every offensive team.
Ice Punch > Payback on Conkeldurr
Celebi or Magnezone or Scarf Salamence > Donphan
Life Orb > Specs, Fire Blast > Overheat, Stealth Rock > HP Grass (if you don't chose SR Celebi) on Heatran
Good luck with your team!
Part of the OU QC team, message
me for a check!