Yes, that means 9 degrees before top dead center (BTDC) or on the minus side of the 0 mark.

I would start there and see how it runs.

My roller cammed, E-brock head/manifold/carb 490 hp 455 was tuned on a dyno which confirmed E-brocks claim of total timing of 36 degrees. Working backwards, my initial timing is 8 degrees BTDC.

And you may want to rethink your intake. We have had a lot of discussion here about the E-brock Performance RPM. The regular Performer is almost an aluminum copy of the RA IV intake (something like that) which was a pretty high performance piece. The RPM manifold is for power in a higher RPM bracket (1500 - 6500) vs idle to 5500 RPM for the plain Performer. Having the power band at idle is probably better for a stock to mildly modified motor like yours and 6500 is probably higher than you want to spin stock rods anyway. It looks to me like you may have more intake manifold than your motor can use and that may cause issues.

Being that engine benchracing is one of our favorite things, I imagine others will chime in here soon.