Originally Posted by oldbogie
They are helpful and usually will clear but you've got to check to be sure. The advantage is if clearance grinding is needed you're not doing it on the head of a highly stressed rod bolt nor the adjacent and supporting structure of the rod. The 12 point headed cap screw will usually clear the cylinder extensions and pan rail also.
Keep in mind these are 5140 rods not 4340, these are better than stock rod materials and are often used in "claimer" competition engines, but this is not top notch super duper racing hardware. They do have several structural advantages over stock rods, the SBC rod wants to deform the cap at high power and RPM settings, this bends the rod bolt which allows the cap to deform which then pinches the rod bearing into the journal wiping out the oil film and welding these parts together. The 5140 rod I aimed you at with cap screws uses a better quality ARP fastener which is more resistive to bending moments, it also uses locating dowels which not only resist the same bending moment but minimize the force from getting into the fasteners and lastly these rods put a larger platform outboard of the fasteners which provides more support area to resolve these bending moments into the larger rod structure. Of course the 5140 material is also stronger and more resistant to these forces. So all this comes together to add a lot of reliabilty to these rods.
oh ok, so getting one set of rods you mention helps in clearance issues and are more stronger than the stock ones... ok from the 2 sets you posted i can use either one? great info btw