Keep in mind that if systems are eliminated and the ECU finds out it will run in Limp mode (depending on what systems are missing) and you'll have an engine that will only be running 80- or 90-percent power until five years down the road you finally decide to do it right like you should have ... and then you forgot how to do all the wiring and now you're in a bigger mess stuck with a performance-limited engine that could be yielding better returns.
If possible, do it right the first
BigMike