To tell you the truth, I liked the stock 420s. They provided plenty of traction. I may have even kept running them, but with the gearing available to me, I couldn't get the Muggy geared right for my setup and I was having horrible cogging problems. I'm running 10/46 with the bowtie MTs and the cogging is better. It only cogs when I mash from a dead, and even then it still isn't stripping spur gears, like it was before. I have a 9T pinion coming. I hope to alleviate the problem all together.