Place cucumbers, onions and salt in large bowl. Stir. Cover and let stand on counter overnight. Drain. Rinse with cold water. Drain again well.
Combine vinegar, sugar, curry and pepper in a large pot. Stir. Bring to a boil, stirring occasionally.
Add cucumber mixture. Return to a boil.
Pack vegetables into hot sterilized pint jars to within 1 inch of top. Fill with brine to within 1/2 inch of top. Place sterilized metal lids on jars and screw metal bands on securely. For added assurance against spoilage, you may choose to process in a water bath for 10 minutes.