hey man i have a 2jzge NA/T is300 im looking towards a 1jz swap i am tuned with AEM FIC 6, if i get a 1JZGTE VVTI with a manual transmission can i just unplug, unbolt and remove my factory engine and swap in a 1jz using my oem is300 wiring harness and ecu? im trying to trace down as much of the wiring as possible, i wanting the same as you, a 1jz but i want to keep my factory is300 ecm since i already have a piggy back on it? what all wiring is required to retain the stock is300 wiring?