Trading engines? Would you....?

[Slik66]

So there is a local car builder that has a 5.3 out of a newer truck, I think he said LQ4. It has been built, bored to 5.7l he said, different heads, cams, intake, injectors... it has no computer so I would need to buy that and it has no power steering pump, alternator or AC compressor.
He said it dyno'd at 558 to the wheels in the truck it was in. It has 650 miles on it from what he says. The guy that had it wanted more power and built a 6.0l. Thats the story...

He wants to trade straight up for my new 383 stroker, 440hp. He is building a 36 Chevy truck.
My engine is turn key ready to go.
I'm just not sure what the value of that engine he has so I don't know if it's a decent deal or what?? Any help is appreciated

Mine is the Carbed old school engine