Anyone using stock ECM and harness?

HotWire uses the older computers to run anything, from 5.7s over 6.1s to 6.4s.
I talked to them and they can not make use of any computer past 2014 because these are hardware-encrypted.

Have a look at the info they provide for computers: HotwireAuto - Fuel Injected Wiring Harnesses
And look at their price list: HotwireAuto - Fuel Injected Wiring Harnesses

Apparently, if you want to (and can) use an aftermarket harness, these are really good quality and price.