I dune with a stock length swing arm, & it's just fine. Sense your going in the trails as well a +6 is out of the question. If your dead set on a extended swing arm then go to a +2. You'll diffently want better shocks , works shocks for a budget is OK upgrade. If it runs good now, I'd wait on motor & just go suspension upgrades first, you'll never regret upgrading the aarms & axle.