If it is a factory Dominator, go to the below Holley reference chart and start at factory settings. 1050's range anywhere from 86 to about 93 depending on the metering setup used and which metering block was used. Later Dominators use more emulsion bleeds, metering was also different between 1 and 2 four barrel carbs, the later HP's are even different still. If it is a modified carb, you need to find out what it came with, some do have lower than 86 to get it right. If you can find out more info, I"ll try to help you get it close.
http://www.holley.com/data/TechService/Technical/Carb Numerical Listing.pdf