10p15C is correct
I believe the Nippondenso 10P15C is the correct compressor for your car ( it was the one on my 87 SDL and was identical to the one I replaced). I don't think there is an easy choice to replace it with another compressor. Any expert opinions on this? It would take some mounting and hose changes. Are there other compressors that would allow the speed sensor hookup? Or would replacing other control items be needed as well?
I agree with the statement above that it is by no means oversized. In traffic on a hot day it is marginal. At 30 mph and above it has done fine in my car in NC, using R134.
If I understand correctly the pulley size will effect rpms of the compressor. A smaller pulley will turn the compressor faster, a larger will turn it slower. My replacement was slightly larger, but still cools well. If your pulley is smaller I would expect it may cool better. Any opinions on this from those with more experience. Can you use too small a pulley and turn it too fast on an AC compressor?