Longer Wheel Studs question

I used these on my 74 duster race car, the are 3" long. Not to bad on the pocketbook. these are the right diameter knurl for the disk brake rotors.

http://www.summitracing.com/parts/MOR-46180/

Great info to know!
Any idea how long the stock ones are versus these?
I only need like another 1/2'' at most versus the stock ones...