Ultimate single engine plane around a T400 or K12 Turboprop?

Could an ultimate propeller powered single engined plane be built around an engine such as the Europrop T400?

General characteristics

• Type: Three-shaft turboprop
• Length: 3.5 m (137.8 in)
• Diameter: 0.92 m (36.4 in)
• Propeller diameter: 5.30 m (17.39 ft; 530 cm; 208.7 in)[9]
• Dry weight: 1,890 kg (4,166.7 lb)

Rolls Royce Griffon

General characteristics

• Type: 12-cylinder supercharged liquid-cooled 60° Vee aircraft piston engine
• Bore: 6 in (152.4 mm)
• Stroke: 6.6 in (167.6 mm)
• Displacement: 2,240 in3 (36.7 L)
• Length: 81 in (2,057 mm)
• Width: 30.3 in (770 mm)
• Height: 46 in (1,168 mm)
• Dry weight: 1,980 lb (900 kg)

https://upload.wikimedia.org/wikipe.../600px-Paris_Air_Show_2017_Europrop_TP400.jpg

Was reading this on an A400M vs a C130J. https://www.militaryfactory.com/air...aft1=820&aircraft2=28&Submit=Compare+Aircraft

Got me thinking once googled the engine spec for the T400-D6 (11,000 hp (8,200 kW) ), could you build the ultimate single engined propeller power plane around such an engine?

Like a really upsized "Turbulence" this has around 850hp.

If you built something 2x the size in terms of frontal area but along the general look of that but with the pilot / passenger sitting above the lump. Where the prop sits vs the main body of the engine looks like it would work well (i.e. main part of engine lower than the prop allowing more of a conventional cockpit position ala P51 (with all the depth of that planes body directly below the pilot).

Like a bit bigger P51, a plane looking somewhere between a P51 and Turbulence would not be massive - obviously bigger than a P51, but would it really be any bigger than say a P47, but with a tad more power!!

The K12 probably too big.

If and Aibus A400M can do 489mph weighing 70 metric tonnes.

Obviously it is a big old lump and the pilot would sit above the main body of the engine

Or even a Kuznetsov NK-12 (?) 11,000 kW (15,000 hp)

You read stuff like this Turboprop - Wikipedia. saying turbo props best below 450mph, but then the A400M is doing 489mph at the size and weight of that thing. Surely if something as bonkers like the double turboprop like the Armstrong Siddley Double Mamba can power the hideous Fairey Gannet.

The main problem is probably how to transfer such a high power into thrust. Counter-rotating prop is a must, both in order to keep prop diameter manageable, and to prevent torque rection for such a huge power developed. I don't know whether the Dowty R391 (the one used on latest Hercules) can be manufactured in couter-rotating fashion. If it can, it is a 2x6 bladed unit, suitable for ~9000 sHP. That's some 2000 sHP short of what engine makes, so the blade diamter will probably go from 4.1m to 4.5m, with obvious need to strenghten the internals.
The resulting aircraft will probably be size of a ww2 medium bomber?

So maybe the K12 with the Contraprops would work (looks like a good frontal area).

The Dornier_Do_335 was fairly big, but I believe the fastest prop plane of WW2, so I'd guess it would be about that size (the engine weight would be less than 2x DB603's easily).

That has a 5.6 or a 6.2m prop even as a Contraprop. But it it had a really long rear like the 335 (but more so), i.e. similar or a bit less length than an the An-22 / Tu-95.