Wiring harness???
 

Is it possibly to not have to extend all of the wires?? And is the purpose of the whole extending just because the wiring harness wont reach the ecu in a left hand drive car? Just looking for as much insight on this topic possible b4 i get started!

In the future you might find people more forthcoming with answers to your questions if you actually ask the whole question.

ANSWER: Yes, the lengthening of the 1JZ wiring harness is because it is not laid out for a LHD vehicle. Some have avoided shortening a fair amount of the harness by bringing it through the center of the firewall. Personally, I'd extend the harness and go for as close to a factory finish as possible.