SBP SG 8.75 Wheel stud size?

Can anyone tell me a good part number for a rear wheel stud for a 67 Barracuda 8 3/4 w/Sure Grip? I see alot of 1/2's but its a 7/16 if its a small 4 BC...If not a part number then maybe the knurl diameter..Im looking for a 1/2 longer stud or a 3" stud I can cut down to fit my closed nuts. Circumstances dictate a 1/2 spacer so I need a longer stud. Doesnt matter if its a LH or RH to me. Thanks.