I'm just an ole' shade tree mechanic so I won't comment on the particulars...lol. I have ran Rudy's version of the 62 in two half mile events. I did inspect it after those events, and have installed the LM21 scatter shield. We will inspect it again while installing the rear gears to see how we are faring. If it shows signs of wear, I will go back to the 65 as well. But, so far I am very pleased with it, and the performance speaks for itself.