I've been very happy with Molnar's quality. The machining and weights were spot on. My 580" with 4.5 stroke motor sees 7200 rpm every pass. I did spin a bearing last year. But it had nothing to do with the rod or crank. I went right back to the same parts. For info read here; http://www.cpbulletpistons.com/tom-molnar-rods-review.php
Doug