I know it's hard o see, but does it look like a dome? No dome = 10:1 or less.
A 12.5:1 motor, even if the cam is too big, should show at least 150 psi.
You can start on the jetting before you get the ignition done, but you must have the initial advance tied down so you know where your throttle disc is at idle. Unfortunately, this will also change if you replace your converter.
As suggested, the Edelbrock vacuum piston spring set will be needed in any case; for now, go at least 1 step weaker on the spring.
Let us know what jets and metering rods are in it now.
This is an AFB clone (counter-weighted secondary air valve), or AVS clone (spring-loaded secondary air valve, like a QuadraJet)?
