I think that the QP-31 has an internal oil sump with an oil pump and 500 cc oil capacity. Do any of you know if that would be the total oil charge, or would I need to charge the normal oil charge plus the 500cc.

I have on of these, it is an '02 with the 7.3l diesel. I love this thread because this is what I have wanted to do to mine. The a/c is just not adequate in hot temps at low speed, especially when in stop and go, heat soaked type situations. I have been looking at the 250 cc compressors too, but I do...