Exhaust gas pressure with a turbo

I am a rank newbie as regards turbocharging, but would like to "do it right," so, in that vein, I bought a pressure gauge to complement my boost pressure gauge. I plan on trying to run as much as 30 pounds of boost on this motor (it has forged pistons, rods, and crank, and the block is O-ringed, so it may not immediately blow up in my face,) but I need some good information as regards the ratio between boost and exhaust back-pressure in the system just before the turbo.

I don't have a clue as to what sort of numbers would consititute an acceptable ratio: intake system to exhaust. I have heard 2:1 is okay, but I am SO lacking in knowledge, I need help with this...

Here is the gauge: http://www.summitracing.com/parts/atm-4325/overview/

Prine?

or, anybody else with experience with one of these gauges. It's an Auto Meter (brand) with a copper tube (mechanical-actuation,) that reads from 0 to 60psi, I figured that was enough range for my application. Was I right?

Thanks for any information...

Oh, the engine is a '64 Dodge, slant six.