the ES bushings were meant to be used with the old subframe "cups"-which is why you have that gap and why you still have the clunking. sure you can use epoxy but you're just half-assing the job. get some solid bushings off ebay for under 100 bucks or from bing, a zilvia advertiser they're the same shit and they work well. or if you don't want to mess around with dropping your subframe you can get solid bushing collars.
you'll see what a mean once you read the instructions for the ES bushings:
http://www.energysuspension.com/asse.../pdf/17486.pdf