camshaft rpm vs cubes

Okay, a fello streeter .
I had a Hughes HE2330 in my combo once that peaked right around 5300 as measured by the Gtec Pro.
I currently have a Hughes HE3237 cam which seems to peak around 5700.Maybe a hair more or less. So thats about 400rpm for 9* more intake duration. I know it doesnt extrapolate linearly, but another 5*, to 237*, Would put you in the range of 5900 to 6000, as others have mentioned.
The rest of my build is 10.7 Scr, aluminum Eddies(stock) with 1.6 roller-tipped al.rockers ,AirGap/750Holleydp, and TTIs.

thats Nice info!:) do you have a 360?
lately I have read Magazines that want to show a tight lsa as the "New" trick to make big Power... they seem to peak rather high even With tight lsa, but I Guess some of the rpm capabilities lies in the heads. on a Stock J or x head, the story would have been completely different.