This is no help at all. Your cam, when installed at 104 will have an ICA of 67 Degrees.Your Scr is stated as 9.7. Comparatively speaking,these are not even on the same planet.
Seriously, the OP asked a simple question: "..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..."
So my response, as clearly stated, gave him feedback on what my experience is with an iron headed 9.7 measured static CR motor. Factory iron heads, open chamber. No recommendations of any sorts, just empirical knowledge based on my powertrain combo.
I clearly did NOT say "...you must run at least [email protected] on intake...or else..." to make this work on pump gas, right?
In fact, here is precisely what I stated: "...My cam is much bigger then what you are looking for though...so this is not a recommendation regarding cam size but rather a point of reference for what is working for me...".