The factory 2.3 rod bolts are the first weak link in the bottom end when rpm and HP is increased. For mild street/strip buildups approaching 300whp and turning near 6000 rpm often, we recommend at minimum upgrading the factory bolts to heavy duty ARP units. For applications exceeding 350whp and 6000 rpm we highly recommend upgrading the connecting rods. Note: The rods MUST be re-sized after installation of these bolts due to the increased clamp load they provide. Any competent automotive machine shop should be able to perform this operation for you at a reasonable cost.