Getting ready to re-build my 2000 3.0 flex fuel engine. Going to machine shop tues. My question is: What is the best overhaul kit? Any recommendations?

 

I've been using Fel-Pro gaskets for the past 30 years.
Hastings piston rings, they've been around for a hundred years now.
Federal-Mogul bearing for your mains and rods.
Just did my 3 litre.

I've been using the same machine shop for 20 years, I can check to see what brand of pistons/valves etc. they used.
The oil pump and the new lifters were made by Melling.

If your machine shop has been there for decades, they usually know what's good and what isn't.

The problem with kits, is that you don't know where the parts are made and what quality control is involved, if any.
The manufacturers that I've mentioned so far have been in business for may decades in the US and I'm pretty sure that they still make the parts in the US, not in China.
Fel-Pro may be the exception, but I think I saw "made in USA" on my head gasket set.

 

I had already settled on Fel Pro gaskets, which I think are sometimes are sold as Sealed Power. I will check for kits with the other brand names you supplied. I am also amazed at the wide range of the costs of these kits.