George,
Very disappointed to hear that you have had a bad experience with your Daytona carburetor. Extra disappointed because I have one still in the box on my workbench that I will be installing very soon. (It has been too here too long now to return it.)
There is a thread on this forum by ClassicsR4Me that discusses his experience with the Daytona UN2 carb. He was having a positive experience with it, as had most of others who commented on his thread.
I decided to go with Daytona because of the rarity of cost of the Carter YF - and because I live at 7150ft above sea level.
I will proceed with installing it on my project as I have it on hand and have already paid for it.