ARP, the world’s leader in fastener technology. There is no substitute for the best! Planning to boost your M20? Building a high HP stroker engine? This rod bolt kit is for you! This kit provides higher strength, more clamping power, and the option to re-use the hardware unlike your OEM bolts. We run these in many of our own builds as well and are 110% satisfied with the fit and finish of these ARP bolts. We offer a 53mm UHL version for those running OEM M20 rods or a 44mm UHL version for those who have upgraded to S50/S52 OEM rods.