Is this an M42 engine?

Or this an M42 engine?

and if the one above is an M42 engine, how come this one is an M44?

Im asking this since today i went to see my Going-to-be engine for my car, and the engine i saw had an intake manifold like the lower two images, while the M42 im used to see has an intake from the shape of the higher image.
So which of them is an M42?
I never thought this can be so time consuming...
i got a harness, an ECU, AFM, all the wirings, but now i dont know what engine should i use.
will an M44 work with a M42 harness and ECU? can i left this matter aside?
Ron.