cam duration

looking for shortest possible duration without having major detonation problems

i have sourced both Lunati and Comp with my complete build and they are suggesting 230 / 236 int and exhaust.
i was hoping something around 216 / 220 (intake) might bleed off enough...I also would like a fairly clean,smooth idle

you guys are over thinking this...
who is running an iron headed 9.5:1 small block with no detonation problems on 91 octane?

for an iron headed small block at about 9.5:1 compression.
..what is the least amount of duration you can get away with
before you have detonation issues.

as mentioned earlier...something that has a smooth idle, doesn't load up and gets fair mileage (read short duration hi lift)
.. emphasis on lo rpm torque,don't want a big hp number,no racing, street car
.. stock 340, 210 / 220 would be fine but i don't think it's doable?

tx guys...new build,looking to get some real world input.
..i have used the XE268..great cam,lopey idle but despite what Comp says,with 3.23 and a decent tire it needs a bit of a converter..i don't want to go that route this time..i think it's 224 / 230... 218 / 220 may work

For those who seemed to have skipped over the OPs posts.
He's not looking for a big cam. He IS looking for the smallest permissible intake duration, commensurate with 9.5Scr, and freedom from detonation.
So, who is running something with an ICA of under about 62 degrees, and Scr near 9.5, and pump-gas;
and what are your secrets?