Help with decking or not?

Scr is a means to an end. The cam will decide the running pressure at the chosen Scr. If the pressure is too high for available gas then you get to start over.If the pressure gets to be too low, the car gets doggie until you start fudging with higher stalls and higher number rear gears.
At Identical Scrs, small cams make more low-rpm pressure than big cams, while big cams may make more pressure at higher rpms.
There is such a thing as too much low-rpm pressure which just makes finding traction difficult while making showing off easy.

Teeners had low Scrs but made good pressure for their intended applications.
Early 340s had hi Scrs , and made hi pressures ; and as DDs make too much for our modern EFI-gas.
360s are very adaptable with a generous swept volume that can be made to pump out the right pressure for just about any application.

IMO, target a pressure,that fits your application, and let the Scr be what it will be.
With iron heads and Quench over .080, 160psi is gonna be close to the limit,for pumpgas, depending on the application. I wouldn't spend much time on decking for compression gain, unless you are struggling at 4000 ft elevation. .012 is only 2.5cc. But at 4000 ft you really need a ton of pressure, so wouldn't be using iron heads anyway. In a tight-Q design with closed chambers, the piston to head clearance becomes much more important.
Chose the cam for the intended application.
I don't see much sense in running a 7000 rpm cam with 3.55 gears, in a 2-gear streeter. The power peak in second is way past the speed-limit, like 90 mph. Meanwhile the neighbors teener correctly geared and cammed for 60 mph, and with the right pressure, gets to spank you.
The 3.55s pretty much dictate not much more than 222*cam, and each higher cam size (in 7* steps) is gonna want about 6 or 7% more gear, so by the time you get 4 sizes up, to [email protected], the chassis is gonna want something like 4.56s, depending on the stall.
If you wanna stomp a certain somebody who has iron heads, go aluminum, crank the pressure up and then you can run a lil less cam than him. There are a few guys here on FABO who have reported running a tic over 200psi, still on pump gas, using aluminum heads. Quite a number of us are between 175 and 185 psi. I myself run 183psi on 87E10, with full timing and a minimum coolant temp of 205*F. Awesome engine with every cam I have tried, always maintaining the pressure.
Happy HotRodding