Mounting Roof Rack to stock crossbars
 

I am looking to build a roof rack out of conduit and I'm trying to figure out the best way to mount it to the roof. Would drilling through the stock crossbars and just mounting to them be a good option, or would it maybe make the rack sit too high up? Any ideas?

I did this before, it's an okay process, but You're better off making/getting some gutter mounts and crossbars that can handle more weight.