Your oars will be a maximum of 1 1/2 inches thick, and most oarlocks are for 2 or 2 1/4 inch oars. To make your oars fit the lock better, you may want to wrap the oars as shown in my first essay on oar making

http://waderweb.com/plans/oars/oars_start.htm

(wrapping will also help protect the shaft.)

I like cheap, nylon oarlocks and I like to get 'em from Duckworks.