Peach tree blight( I think)
I think you are referring to Peach Leaf Curl. I'm unsure if lime-sulfur is marketed to home gardeners anymore. I searched the WSU database on registered pesticide products and found no products registered for home use in Oregon. Below is the discussion of this disease from the PNW Disease Management Handbook. It will describe the disease as well as list fungicide options. Feel free to write to my email address below if you have questions. Thanks!