Duramax - standaloneharness * Every Duramax Harness is recovered with new GM Spec High Temp Loom and High Temp Harness Tape. * Express Van and Savana harnesses can also be converted. (they will be significantly simplified especially the trans section) * Pricing is $541 for a Truck Engine to Chassis Harness and $636 for a Van Engine to Chassis Harness. Duramax Standalone Harness – Swap Specialties Looking for a Standalone Wiring Harness for a GM Gen3 4.8, 5.3, 6.0, or 6? What about a Gen3 5.7 standalone wiring harness? We got you covered! Standalone wiring harnesses for GM LS, LT, EcoTech, Duramax and more.