There's 4 of us in New Zealand now running well sorted NSR300s. We all have them to similar levels of tune with some differences between carbs and reeds etc, but below is the spec of my one.

https://youtu.be/bmQl5_T-Jz0- A couple laps on the machine

-Tyga 300 barrels and pistons (Running different deck height and slight porting changes)
-Cases matched to barrels and increased case volume.
-Tyga Chambers (best one's we've tried to be honest!)
-Custom machined inserted cylinder head (not VHM) Compression is as 15.9:1
-Running total loss with Tyga trigger wheel
-Ignitech ignition with mapped power valve and ignition curve and quick shifter
-Custom made wiring loom to delete unwanted wiring
-Stubby HRC spark plugs and caps.
-PJ38 carbs with RS250 inlet manifolds (stock reeds!)
-Custom front and rear subframes
-GSXR k8 forks and wheel up front in custom triple clamps
-Honda RS250 rear wheel
-Ohlins Rear shock and soon to be cartridges up front
-Tsubaki Racing Chain on Tyga Sprockets
-Tyga Handle bars
-Tyga Step kit (with modified and shortened foot pegs)
-Tyga Bodywork

Still in the process of getting the chassis geometry and suspension dialled, however the bike is showing awesome promise getting within 1.5 seconds of the lap record at my local track on it's second outing. This lap time was done on old tyres and a bone stock NSR250 front end which left a lot to be desired.

Power output is at 85hp peak with a good spread from 8k-11.5k With the over square engine revs are severely limited to 12k topped out but with the spread of the power it's not the end of the world. It also gives the crank a much easier time. I'm lucky enough to have a dyno in my workshop so quantifying any changes and comparing results of different parts is easy. It's been a slow process to get up to this power but it certainly noticeable on track. Our competitor in this class is a called a Ozzy450 which takes a modern 600 and removes one cylinder. They are very fast and can get 90hp with the spread of a 600 which makes them very competitive. They hold the F3 lap record at all the tracks in NZ now I believe so it's time a pesky 2 stroke came and upset the apple cart!