A very very nice bit of information from Mr Graham Russell showing the differences in castings 202 vs 295 vs std 998 cc head in glorious cut sections. And the reasons why he likes one casting over an other. I must say it is very nice and enlightening..
If you look at his throat design and look at the aperture it looks quite a bit like what I would expect to work well from a theoretical standpoint.
Just squint a bit and look at the negative green shape. Also note the angle of the chamber wall at the short side.
Also note the use of multiple back cuts on the valve and the use of a big valve on a small throat/bowl enabling him to get a decent shape in the aperture.