The car is an 84 E Class with the mitsu engine. I am not afraid of electrical and would like to do the upgrade to SMEC for a 2.5 as that is what I am most experienced with. So with that being said, what is the best course of action? Can I get a SMEC harness and splice the engine controls into the bulkhead connector as required? Will things like the digital talking dash still work? Or does every wire in the car need to be replaced (I dont really see why that would be necessary, but enlighten me)