Your high-pressure reading doesn't suggest "overfilll" to me.
The suction pressure seems high. Is there any reason to suspect your compressor has been compromised, that it's not pumping like it should?
One other thing: Evidently there's some confusion about where the orifice tube resides on the Suburbans with rear air. See here:
We put the orifice tube in the line by the evaporator core just like on pickups, but there wasn't one in there to begin with. So are the Suburbans not supposed to have one there and have it instead in the location of that diagram or should it be in both? (for someone's benefit in the now or in...
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