I'm pretty sure much like the Stelvio, the Alfetta will be sharing the engine and transmission from the Giulia and QV as well.

I really don't think there's any difference in spec between the Stelvio engines and the Giulias. Maybe some minor transmission tweaks for hauling purposes in the Stelvio but.. even that I doubt.

Anyhow, we can guaranteed look towards those as I doubt that'll be changing for a while, when we are trying to think of what will come in the Alfetta.

I'll list them below.

In N/A we have:

2.9L V6 Twin-Turbo producing 505hp and 443lb-ft of torque (Quadrifoglio)
2.0L 4-cylinder Turbo producing 280hp and 306lb-ft of torque

Now there is also a diesel option which is:

2.2L 4-cylinder Multijet II that produces approximately 205hp and 350lb-ft of torque

Even with the 2.9L V6 Twin-Turbo, the Alfetta won't have the mind blowing performance that the Giulia has, mainly due to the increase in size and body weight. That's the trade off for more cabin pace, unless they can tune it to produce even more power.

I'm sure they can but I don't feel like they need to at this point. Being in the 500hp range still keeps them as a performance sedan and it's meant to be more luxury and executive rather than a sport sedan so in my opinion, I think it's just fine.

How much power do you think it should have?

We should also be discussing hybrid powertrains because being owned by FCA, there's a high chance this time around we'll see Alfa's first hybrid.

They are entering an era where hybrids are at the top of the performance vehicle food chain if you know what I mean. It's an easy way to say ahead of the game.

That would be great but the only hybrid powertrain I think I know of from FCA is more geared towards efficiency. If they were to make a performance oriented hybrid powertrain and stuff it into the Alfetta, that would be genius. It would be that extra hype that could carry it a far way and set it apart from it's competitors.

That still doesn't negate the fact of potential because its high volume products like the Pacific Hybrid that help to fund bigger, better and fun projects like this. With that technology that can be passed on and further built on. They don't just build this stuff with one model in mind or one type of application.

Well obviously they don't build a powertrain for just one model and solely one model. It'll get shared throughout. But yeah the hybrid tech can be utilized still, it's just using the bare essentials of it and producing something that'll actually have some performance in it.

The same Pacifica system can be used in other Chrylser and Jeep products but doubt it'll fly in something like the Alfetta

Not the entire system as we know it but certain parts of it, is possible.
You see it happening with a lot of other similar things. Taking traditional engines for example, sometimes a car maker will use the same block/bottom end/etc. from model to model, but from model to model it seems completely different.

Perhaps even just the electrical part of it solely and transferring that to a completely different head/block combo. That could also work out. Like how Toyota shared their Direct Injection recipe with Subaru to create the twins or something?

Correct. Components necessary for its type of application will be changed instead; voltage wiring type, battery pack capacity/size, brake booster, electric motors, etc.