That is close to what I got last time I checked the 83 (at about 150k mi). It has the first edition of the B23F with 10.25 comp. ratio. I later had the head off for other reasons and there was not much in the way of deposits in the chambers or on piston tops. And there shouldn't be with unleaded, high-detergency fuel, and electronic fuel injection.

Your numbers seem somewhat high for a B230, so possibly gauge inaccuracy or some carbon in the chambers. But the important thing is consistency between cylinders and you have that, so no worries. I would stay away from any attempt to remove carbon by pouring anything into the engine. If it runs OK and gets decent fuel economy, leave well enough alone.
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Bob: Son's XC70, daughter's 940, my 81 and 83 240's, 89 745 (V8) and S90. Also '77 MGB and some old motorcycles