Probably best to compare the 6.4 apatche

Also one thing at a time strting at the bottom

Much Lighter crank with smaller journals.
Much lighter rods with a narrow smaller diameter bearing.
Much lighter pistons, much shorter compression height has less friction, also has less friction from teflon coating. Much thinner rings for less friction(this one may be harder to retrofit more on that in a second). Smaller wrist pin is much lighter and smaller for less friction and I think the 6.4 is a floating pin.
All that adds up to a rotating assembly probably slightly over 1/2 the weight.

Much better oil control (this is why the thin rings work so good), the new hemi has all the oil from the head diverted outside the block down through big passages cast on the outside and they dont drain freely into the pan till they are below the windage tray witch also is much better at scavenging oil from the rotating assembly. Another thing is the much tighter tollerances in the bearings and piston fit, much less oil flows through them and they are much more round and less taper.
This all adds up to a lot less oil flinging around on the cylinder walls and crank. If the rings are not drowning in oil they can keep it out of the chamber easier with a thinner lower tension ring. It also has a dykes style second ring for even more efficent rings.

The cam is larger diameter to make it more rigid and it is higher up in the deck to give a lot shorter lighter stiffer pushrod. Also the VVT helps a bunch, it eliminates the need to a EGR valve to keep cylinder temps down, it just retards the cam timing to bleed off cylinder pressure, this retarded cam timing allows the cylinder pressure to also push on the piston a few degrees longer to make a little more use of the fuel that was burned. Thease aspects of the cam are all gonna be a challenge to retrofit into your 383.

Onto the valve train, the pushrods I mentioned already are very light, the valves are small diameter stems and also very light, the small guide also reduces friction and increases air flow. The behive springs have a very light retainer and keepers. All this light weight stuff means less spring pressure is needed to control the valve and that also reduces friction. Also those behive springs tend to be better at reducing valvetrain harmonics again meaning less pressure needed. With some money thrown at your 383 you could greatly reduce the valve train weight.

The combustion chamber is insanely better, 2 spark plugs nearly centrally located instead of one at the very edge of the chamber. Dual squish pads. Valves that moves away from the cylinder wall as it opens instead of staying right next to it. Also they are aluminum. You could buy some trickflow heads to improve on the metal choice, squish/swirl part of the chamber and offset the head location to improve valve location over the piston but it gets complicated to do much here but at least air flow would be much better than your 906 heads.

The intake is much better than anything out there for a 383, long, equal length, high flowing, gently curved runners, plastic to keep the heat out of the air, MPI for perfect air/fuel distribution... maybe you could get a 3d printed plastic one made for your 383?

The MDS would be nearly impossible to incorperate.

Crank driven oil pump is nice, it means less load on the timing chain and no drive gear train to wear (less moving parts is always nice and makes things quieter).

The block is much more rigid so less flexing of the cylinder walls for better sealing and less friction on the crank from distortion of the bearing housing.

COP is better than a distributor because there is going to be less flex and vibration in the cam and timing set as timing is measured directly from the crank. Coil on plugs could be done, they allow more precise timing and lots hotter spark because you don't have to worry about arcing in the distributor cap and each coil can recharge longer before it discharges and the shorter path from coil to plug means less resistance.

Then you add in the sealing improvements like one piece rear main seal, awesome steel core flat pan gasket, rubber o ring type valve cover gaskets, o ring intake gaskets, no open oil under the intake (also helps keep heat out of the intake). O ring style timing cover gasket. O ring water pimp gasket...

Many of the improvements work together to allow a much higher compression ratio that also improves HP TQ and MPG.

You could add a bunch of the improvements to your 383 but they will cost a fortune and some are just not reasonable to bother trying.