I don't know how much any of the cards I'm about to talk about are but I know when I went into my first modern tournament with my old standard deck after tweaking it was a solid deck and was fun as hell for me. Did it top 8 hell no... Well it did a few times but it's not like that

Dungrove Elder > Leatherback Baloth

The only thing baloth has going for it is the 4/5 on turn two. Dungrove has hex proof and honestly can easily match a goyf. In a turn or two and gets bigger. Strangleroot geist you already play but he's just all around good and he's comes back lol. Vengevine is always good if you have a fair and reasonable amount of creatures to revive him. Garruk primal hunter is just great in standard I used to have a dungrove elder and by the time I played garruk made a 3/3. Next turn draw cards from dungrove's power and usually after that you had more that enough to win.

Rancor is always nice but again I don't know the $$$

As i've seen a few others mention, Dismember seems a little strange here. I'd rather see more copies of Prey Upon if your meta has creatures you need to kill (presumably just combo decks?) Generally though, I haven't typically seen mono-green running any removal at all (at least mainboard). I'd also advise the full playset of the Aspect of Hydra - those cards are busted and just seem too valuable not to pass up.

I seriously love this deck. It annihilates Tron and UW control 90% of the time. Have you considered playing Pendelhaven as a 2-of?

vortexgrey I will consider Pendelhaven. It might be a bit costly, and wouldn't be a huge buff to the deck, but it is worth considering.

@TreeGobo, it only adds a few bucks, but it can spice up an otherwise unremarkable Experiment One or Pelt Collector. Speaking of which, why play only 2 Pelt Collector and 4 Experiment One instead of 3 and 3?