Here's a website where you can calculate the compression ratio of your setup.....there's a few out there.
Few extra bits of info you need:
I assumed 30 thou over bore, ie: 4.030
Gaskit thickness: 0.040
Gaskit bore: 4.100
Engine Deck: 0....have you had it zero decked?
Just want to confirm you have the dome pistons and not the standard flat top with a 3cc valve relief? You described it right with -3 as being a dome and just 3 is a flat top with valve reliefs.
With the pop up piston it shows 11.8:1 and with a flat top with piston with 3cc valve reliefs it's 10.9:1.
The alloy heads on these clevos can get rid of the head much better than the cast iron ones and can take more compression. The chambers are also more efficient in design and you'll find you won't need as much timing to get your peak power. eg: good set of CHIs will make power at about 28-30 whereas some cast iron heads will need more at about 35 degrees total.....just generally speaking.
Is 91 the highest octane pump fuel you guys have...or do you have up to 95? can't remember! If you're at 11.8 I think you'll be on the limit with that cam.
You also need to look at how heavy your car is and what your rear diff gear is and stall converter rpm. If you're running 2.9's, 3500lbs and a 2500 stall, it'll kill ya!