For everyone who is saying Magmortar Lv.X and Heatran Lv.X make a good combo, good luck getting it out quickly and consistently. 2 Lv.X's = slow. What lines are you going to play to make the deck consistent? 3-2-2 Mag and 2-2 Heatran mean more consistent Lv.X's, but not for the normal forms. 3 or 4-3-1 Mag and 3-1 Heatran make consistent normal forms, but non-consistent Lv.X's. A 100 snipe every 2 turns is nice, but just not worth it.
However, Heatran and Typhlosion decks are looking good in my book. with Heatran Lv.X, you are doing and renewable 100 damage per turn minimum, which makes a bit better than Mag Lv.X (no sniping option, but you can do it every turn, plus Rare Candy-able Typhlosions and a Lv.X are quicker than 2 Lv.Xs, but Heatphlosion will need a starter).
Maybe Heatran Lv.X + Infernape (DP)? Lower damage output, but probably a little faster. Would require 2 Heatran Lv.X's to work best.
To be honest, no matter what you combo Heatran Lv.x with, as much as I want it to be good, will just probably be too slow to be good enough. However, we will have to wait and see.