We’ve figured everything out for you with our Camburg heim kits. You just need to select the heim and bolt size you want to use along with the thread direction and tubing size. These kits use FK JMX & JM series heims, our 4130 chromoly thread bungs, our heat-treated stainless steel mis-alignment spacers and the matching steel jam nut. Everything is Made in the USA and not some cheap imports. Use these to build upper or lower control arms, spindles, trailing arms, etc. Refer to the diagrams for sizing, spacer spread and degrees of movement. The JMX series are stronger heat-treated alloy bodies for racing vs the standard mild steel JM series.