Anyone using stock ECM and harness?

You will need to get a thermostat housing with a bung for a temp sender for your gauge. You cannot tap or put a T on the factory temp sender. Depending on what gauges you use. I used Speedhut gauges with GPS speedo I believe if you use factory speedo you will have to get a converter for it.

Would this work?
https://www.diyhemi.com/product-page/dual-stealth-waterneck-spacer