Because domed Hemi pistons are heavier than wedge pistons, you really need to splurge on good rods. For the sake of comparison, the standard 440 forging on the left (840 grams) is marginal at these power and rpm levels. The middle rod is a Six Pack forging (882 grams). Its wider beam adds strength, making it slightly more durable. We're going way beyond, so we used premium Crower 4340 lightweight billet rods (869 grams). The 2.20-diameter big end is smaller-and lighter-than Chrysler's 2.375 for a compact package that'll handle up to 1,000 hp. All rods measure 6.770 center to center.