The Silvertop con-rods are certainly solidly designed and with bolts weigh in at 506 grams each (without bearings). The Blacktop was fitted with thinner, lighter and weaker rods that happen to be 485 grams Every. Both are readily interchangeable and use a similar fasteners for the primary bearing cap, as https://andyrpoli.blogacep.com/36549000/little-known-facts-about-4age-20v-itb