Leave the stock computer in the trucklet, and then add the VW engine and computer to the trucklet.
wire the VW to it's computer and leave the VSS and other stuff needed to work the Zuki stuff hooked up
cull out all the unused wires fron the VW computer, and just leave the required to run wires in the harness
The only shaired wire I think is the coil, swap over the sensors from the Zuki to the VW engine so the guages
work like they are supposed to and call the thing Frankenstein when ur done
Don't sound that hard does it
Wild