OK.. long ramble warning.
so Richard Holdener...nothing wrong with the guy. I've seen this guy's articles from the 90s when businesses would throw parts at these magazines writers for the advertising. picture long nights in a dyno trying to make a combo work in a way to put their parts in a good light. and then show that combo.
so you got a new high flow head, well you don't bolt the heads on a stock engine to show a performance gain. you put the stock heads in a big cam, big displacement, high compression engine. make a pull, swap on high flow heads. make pull, numbers go up.. parts sell. it's not dishonest in anyway, but it is a tad misleading. you have a part that's marketing low end tq, you bolt it on a reverse combo.
so he's got all these saved engine dyno charts from different combos tested over the years. he picks a subject for tonight's live and then shows the charts that back up what tonights story line is. all very interesting and entertaining. I've watched a few myself.
but the part that's a bit dishonest in my opinion...we all thing we are learning something special but none of that pertains to your real world driving experience. he's got an engine on a dyno stand, free flowing well tuned for Scavenging exhaust, no accessory load, aftermarket stand alone ecm that's targeting best air/fuel ratio for power and timing. 100 octane fuel to remove the variable of knocking and wot from whatever power band he wants to show you.. either 3k to 7k or 2500 to 6k. he is open and tells you all of this but if you don't understand how that pertains to your vehicle and driving style. you are left with almost completely useless information. say your combo, and I think you're wanting what 90% of us want out of our daily driver.
your stock exhaust is unturned for scavenging, you have tons of accessories on the front, your stock ecm is targeting 14.7:1 air/fuel. (to lean for power) anytime it's not in power enrichment mode(PE usually to rich for best power to be safe on the street) piss water 87 octane. and you're never or hardly ever at wot max load at say 2k rpm, and definitely not running out to 6k often.
so as you can guess, you can take the engine off his dyno stand that seems like it would be perfect for your driving style, bolt it in the truck and never hit the perimeters used during his testing. it's just not really relevant.
in my opinion, the transmission tune, and if it's 4 speed, 6 speed or new 10 speed, along with axle gearing has more effect on what you're trying to get from your truck than even 40hp or 40tq moved into a different rpm band on your truck. what you're looking for is throttle pedal mapping. the feel of it being eager to run at 1/4 throttle. in that way something like a pedal commander and a good tranny tune would go further towards your goals than anything you're going to be able to build using different heads.
I drive lots of ford's, fleet junk. but one thing I believe they do much better than gm is the throttle mapping. they always feel like they want to go. they tune their trucks that way where even a gm car that has sport mode will need to be turned to sport to feel that way. this I believe what sells on a test drive and really what we all want from our mods if we aren't going to drag strip or lineing up next to our friends for a little grudge march.
as for what you're looking for, I believe gm built basically that combo. the LFA they stuck in the hybrids I would hope is the more efficient combo for daily driving, cause gotta have a little faith in gm engineers haha. it's a aluminum 6.0, so lighter and smaller bore works better in theory to control detonation, allowing for your lower octane 87 than a 6.2 bore. (this is said to be why gm loved the 305ci in the 90s smog era, small bore better mixture inside the cyl during compression stroke) the Cathedral Port heads for higher speed airflow in the intake port at lower rpm(better filling). they also raised the compression, but mainly because of the cam they went with. late intake closing, it bleeds off a low of compression at low rpm, say idle to 1500 for a cleaner charge from there up. you wouldn't want this cam, it would feel super lazy, but not 100% sure you could run 87 in it with a normal cam on that higher compression. they cover for the lack of off idle tq by using electric motors, but even then the throttle map in the hybrid is more loft down the road on a magic carpet (cvt tranny keeps it at that stead efficient rpm while mph increase too) than race from light to light but something like that with a normal cam and compression, might get you the best hard parts for 87 octane and 2000 rpm tq at lean part throttle a/f, but it will all be in the tuning of making the throttle mapping feel right and the tranny keep you in that band just right.
so yeah.. in the end, it's best to keep the combo you have and do the longevity mods to make it last 300k than anything else. that and vvt is your friend, try and keep that active even if you build something new. they don't really fail and it's free tq.