To start an engine needs compression, timing, a sufficient quality spark at the right time, the right amount of fuel being correctly delivered into the cylinder and a decent cranking speed.

That your engine isn't starting means one of those requirements is absent. Which one is for you to discover.

I suggest you revisit such things as the firing order, position and function of the essential sensors, valve timing and ignition timing and suchlike, comparing the original motor carefully with the replacement.
I once heard about a guy who had replaced an engine assuming the automatic transmission donor engine would be identical to his manual transmission one. They weren't! It took a deal of research until he discovered the ECU and crank sensors were different meaning the ignition timing was miles from where it should be. This was a Ford.

Even though computer controlled timing can't be adjusted, it can still be checked with a stroboscope at cranking speed to ensure it is in the right ball-park.

When you are confident everything is as it should be, if it still will not start I suggest you try spraying ether into the intake. If it fires and briefly runs it can be assumed everything is serviceable. Sometimes if an engine of a certain vintage doesn't "catch" straight away it gets into a bad uncooperative mood.

Try disconnecting the fuel pump and cranking the engine with the throttle held wide open. That often produces surprising results.

Good luck!