Connecting rods are extremely important which doing an engine build or updating your engine. We offer multiple different style of connecting rods that you can choose from. Our 40hp connecting rods are reconditioned for a 1961-1964. Even though they are reconditioned, they have been re-sized and new pin bushings have been installed. Our reconditioned balanced connecting rods are rebuild with the same standards as our stock rods, only they have been balanced end to end for total weight. Of course we also have our new connecting rods that come to us straight from the factory. The new rods are sold out right in a set of four, where as our reconditioned rods will have a refundable $25.00 core charge. While changing out your connecting rods, you might as well get a set of connecting rod bearings that are the thickness you're wanting. We offer .010, .020, .030, and .040. Please give us a call at 1-800-955-9795 and we would be happy to answer any questions.