Have you priced it? They want a pretty penny for the kit. They make two kits, a bolt on and weld on, I believe. JMax something or another is probably the brand
JMacx

GVM/GCM Upgrade | Coil Conversion | 6x6 | 4x4 Accessories | JMACX
Looking for ride comfort or would like to carry and tow more weight? JMACX has the worlds most trusted coil conversion and the highest GVM/GCM upgrades.

Basic kit is $18k USD