Ls400 Woes

[LS400VVVTi]

Hey all anyone with any information would be an absolute hero at this stage!

I have a 1996 Lexus LS400.

Now here is where the issues start, I had purchased a replacement 1UZFE engine with ecu, engine wiring loom, immobiliser, key, ignition barrel, afm… the whole works and jerks.

However it is the later VVTi version and by the looks of it uses fly by wire throttle and also the two spare plugs from the ecu obviously interface with the auto trans and the dash functions etc.

My question is this.. Has anyone gone down this road and had success without costing an arm and a leg or should I sell this on and get a non VVTi version that directly drops in?

Cheers