The left flywheel pictured is the sooner Silvertop design and style whilst the best may be the lightened Blacktop. To cut back sounds the Blacktop belt featured a slightly unique shape enamel profile, This really is to the belt only and also the profile on the travel / driven pulleys(s) https://beaudxofv.blog-a-story.com/21315085/an-unbiased-view-of-4age-20v-blacktop