Mopar Small-Blocks. Larry Shepard

       The 340 forging is the only A-engine connecting rod that has a bushing for use with a floating pin. It is difficult to see the bushing after it is installed but you can see the small step in the machining at the pin bore, which is just the end of the bushing. This bushing cannot be added to the standard forging used in 273/318 engines because there is not enough material around the small end to support the bushing machining.

      The H is actually a heavy-duty rod designed for extreme performance and racing. Keep in mind that Scat and Carrillo do not publish weights for their H-beam rods. The K1 H-beam rods weigh 656 grams with 7/16-inch bolts. However, I don’t think 7/16-inch bolts are required for these street applications, but they are a nice plus if they don’t add weight as does the lightweight Scat design.

      Dyers and other billet rod manufacturers offer H-beam rods in four categories: light (585 grams), ultra light (575 grams), super light (540 grams), and heavy (600 grams). Billet rods are best suited to special-application engines, such as race 305 engines with 2.96-inch stroke.