Not to hijack your thread here, but I have a similar issue. I have an LT1 in a third gen car, that now has a 78mm turbo, and is intercooled. Same deal as you. It wants to run 220 all the time putting around, up to 240 if I run her harder. Previously, same cam, heads, etc., it ran 180 all over, with only 1 fan hooked up (fourth gen fans / radiator swapped in), and the fan was rarely needed (stock radiator still too).
Now with the turbo and intercooler, sitting in the garage it'll climb up. I'm really surprised, I put all the plastic deflectors, air dam, etc., back on there too, and the temp slowly rises up.
Did you figure yours out yet?
91 Camaro Road Race American Iron car - The Menace
91 Camaro RS - '93 LT1/T56 swap project, 10.5:1, 224/224 @.050, 60lb Deka, home ported heads, 78mm Vs Racing, intercooled, 2 bar MAP tune on $DA3