Mercruiser Marine 5.7L V8 330 hp Black Scorpion fuel injection system rebuilding

There are not too many videos on this engine, so I will try to add as many videos as I can in the future. Sorry for the bad sound.
These are the special tools you may need:
Crescent 3 Pc. Flare Nut SAE Wrench Set - CFNWS0
Mission Automotive Dielectric Grease
Seals for Fuel Injector 805225A1
I had to replace the fuel lines. They had some damage and the person I bought the boat from improvised using car fuel lines. I got all new original lines and had to assemble them.
FUEL LINE ASSEMBLY - 32-861568001

[@NoSmileification]

Is the lower intake manifold a synthetic/plastic? I know the other MPI intakes are iron (I believe). The upper looks like steel or??

[@ItaiLeshniak]

The upper part is Aluminum