Used HD gassers are a dime-a-dozen everywhere you go. Everywhere, on every used car lot, every buy-here, pay-here redneck express car lot in the world.
And they still can't give them away.
Construction Companies bought cheby 2500's with the Vortech 6.0 by the dozen for Foremen to cruise from site to site. So did Cities, Counties and States. Go to a goobermint auction and you'll see a bunch of them. Drive down to Miami along 27th street where all the junk sits waiting to be shipped to South America on the rat-infested barges siting there and you'll see even more. The same can be said for Super Duty's and Rams (not quite as much, though).
If you need a HD truck, get an HD engine. Otherwise, what's the point?
The new F-150 3.5L EcoBeast makes 500 lb-ft of torque, which is substantially more than any of the HD gassers. So, why even bother??
If I don't get another Cummins (the War Department hates it [which is good reasson to keep it]) I'll get an F-150 with a 3.5L EB. They are seriously bad to the bone.
And I forgot to ask..... Does the cheby HD come with a ten speed transmission these days? The Fords do. And teh 7.3L Godzilla engine is pretty badazz for a pushrod motor. A step backwards for Ford, tobe sure. But they did it so it would fit in all those Van Bodies they use for Class C Motorhomes. And they use a ton of them. A pushrod engine is more narrow and the 6.2L OHC was getting long in the tooth anyway
Google the 2021 chevy 5.3 valve springs while you are at it..Get back with us your findings.