Biggest thing is a comm cut, straight outta the box. MVP arms were notorious for coming with their comms WAY out of round. That solves 80% of the problems. Replace the stock brushes with Reedy #767s. Next thing to go is the little plate spring between the brush hoods and heatsinks. Just drags on the brushes. Trinity blue spring on the positive side, do a good job of shimming the armature with Teflon shims, align the brush hoods with a bar & rod (not those P.O.S. "H" things), and when it's all together, lube the bushings and add a couple of comm drops, then break it in submerged in warm tap water for 10 minutes at 3.3v. Pull it out, dry it off with compressed air, REALLY dry it out with motor spray, and re-lube the bushings.
You can also get fancy and narrow the faces of those #767s, but it's a real trick to get it right with a Dremel. But done right, it will throw the RPM-happy powercurve a bit towards the bottom end for truck use.
Biggest thing, MVPs overheat. They just do. 170°F at the side of the can is pretty normal. I think that's what spooks everyone, they think the motor's about to grenade and they gear it to the moon until it'll pull stumps but won't go anywhere.
Little bit of elbow grease and some faith in their durability, and you can make MVPs rocket