4. The rods in these late-model engines are made of powdered metal and use a cracked metal design for alignment with the bearing caps. Made in a manner similar to both casting and forging, the metal powder is put in a mold, compressed, and then heat-treated. This process results in a strong lightweight part that uses less waste and ends up with a very uniform grain structure. Plus when the cracked cap design is used, the grain of the metal acts as an alignment grid to help fix and strengthen the rods. Turnkey uses these stock parts for most of its crate engines, but it does upgrade to forged pistons and ARP rod bolts to overcome some of the weaknesses of the original cast pistons.