Look very closely at that photo, and see if you can tell what’s special about this new Ultra Xd connecting rod from Callies – it’s pretty subtle, so take your time and don’t feel bad if you don’t see it right off the bat…

Figured it out yet? Look again at the parting line between the big end halves, and you’ll notice that it’s slightly offset. This patent-pending design slightly cants the rod bearing housing bore to give stroker engines room to run bigger cams. Callies says that at a minimum, you’ll gain an additional .050 inches of clearance with an Xd rod, compared to a symmetrical design.

Ultra Xd Rod Features:

• High strength 7/16 Ultra or Custom Age 625 Cap Screws
• AMS 642 Bronze Silica Alloy Wrist Pin Bushing
• Machined from Premium Purity 4330 Steel
• Available in select sizes for LS and big/small block Chevy

The Ultra Xd joins the Ultra connecting rod line, as well as Callie’s Ultra H-Beam “high value” rods that use the same premium materials as their I-beam brethren but cost less to manufacture.

Of course, Callies continues to produce their renowned crankshafts – the lightweight Magnum XL, the competition proven Magnum, the made-in-the-USA DragonSlayer, and the Ultra Billet, which now features the Aero-Shed surface finish. In addition to the unique Ultra-Shed counterweight profiles designed to gently move oil away from the oncoming rod journal and direct it out of the path of the following counterweight, the Aero-Shed finish produces a crankshaft that is free of stress risers and aerodynamically efficient.