Just a thought...instead of drilling them out now for studs (which is fine in itself of course IMO), if the threads in them are 1/2" already..why not just use screw in studs from the rear like the style used on rear axles and commonly sold? work Might save a step and some time at least...

http://www.summitracing.com/parts/msr-8002/overview/

There are plenty of different brands out there, but those as an example at least.