Eagle "SIR" I-Beam rods are intended to be a budget-friendly alternative to O.E. rods. Minor design changes and the use of 5140 steel, which is typically an improvement over O.E. rods, result in our "SIR" rods being stronger than most O.E. rods they are designed to replace. To what degree depends heavily on exactly how good the O.E. rod is. To help convey the intended application we recommend, an approximate power rating of 500hp for small blocks and 700hp for big block applications. Most applications are available in either press-fit or bushed for full-floating piston pins. All rod bolts are ARP capscrew style bolts. Alignment sleeves are used to precisely position the cap. This replaces the old "wavelock bolt and nut" system which was not easily assembled or disassembled. ARP 8740 bolts are stanard (3/8" on small block applications, and 7/16" on big block applications). ARP 2000 bolts are available at additional cost for most part numbers. Because these rods are commonly used in stroker applications, attention has been paid to the are of the rod that would contact the cam in Chevy small block applications so that adequate cam clearance should exist without the need for a small base-circle cam. While it is impossible to test-fit every cam that exists, it is always best to confirm you have at least .050" clearance between the cam and the connecting rod. Eagle "SIR" rods are recommended for use in naturally-aspirated, gasoline, performance street engines. Eagle "SIR" rods are not legal for use in pollution-controlled vehicles.