53’ 4 blade prop

A good prop shop is best to answer those questions
You should turn up 2300 correct? Typically add 20/30RPM when tuning the props.
Cruising speed is 70% load should come in 1925 +/-
Divide your single engine hp by 16. 800/16=50 gph both engines at 70% load (1900-1950)
See how that computes

Yup, those engines should indeed reach 2300 rpm @ WOT.
And I agree that a good prop shop should be able to:
1) check the existing REAL pitch of each prop, possibly/hopefully verifying a slight difference between port and stbd;
2) re-tune the props, shortening them just enough to achieve the rated rpm - or maybe 2350, for good measure.

On the other hand, I don't understand how can you suggest any cruising load/rpm, though.
If the OP has the 1000hp 12V MANs, the exact model he's talking about must be the D2842LE401, which is a fully mechanical engine where you have no way to know the load, at any given RPM (WOT aside, which is 100% by definition, since he can't reach the rated max rpm).
By looking at MAN curves, the optimal running speed for those blocks (max torque and lower specific fuel burn in g/kWh) is around 1800 rpm.
And considering that 24/25 kts is a pretty decent cruise speed, I'd stick to that even if the engines as such could withstand running at 2000 rpm practically forever.

Again, based on MAN curves (prop demand), at 1800 rpm they should burn 26 gallons each (and 30 @ 1900).
But that's all a bit theoretical, based only on an estimated typical installation.
Any actual boat, and its conditions, can affect these numbers significantly.
The only way to know for sure, lacking electronic engines with their fancy displays, would be to retrofit some fuel flow measurement system, and check in real time how the fuel burn changes with rpm/speed.

2" less pitch would be the right answer. BUT, you need a prop shop to scan what you have, then recommend from there/

Propped correctly I cruise MANs 1950 rpms and they like it there.