the factory is basically the same as the evo2 or tir. But it does cost quite a bit for the upgrade. you will need to purchase bulkheads, short arms. hinge pin retainers, rear shock tower, captured rod ends. and if you really want factory lighted diffs and lighted hex drives. you are looking at well into the $200 to make it factory. And I know there are places that are sellign the factory for $289 or so