I'm trying to find an 848 casting locally bad enough to scrap, but good enough to saw up in a few planes to find where the ports can be improved without getting a bath.
According to Bell, for a siamese port the area should be slightly larger than the valve area, so if a 1-7/8" valve is used, the port should be something like 1.90" ID, which of course is impossible (this is 60% larger than the existing 1-1/2" port). It looks to me that the port ID may be the real choke point that makes any major revision of the intake unproductive.
This is why the lump port works on the 250/292, and not the 235 - the much wider late port has enough area that some can be traded for a better shape; with the 235 there's no room at all.
I agree that more peak lift won't help if the port doesn't flow enough, but a higher ratio also "stretches" the entire duration and especially the overlap triangle area and IMHO will help a mild engine with a stock cam.
