If they are real SPS bolts, they're probably as good, if not better than ARP. You can always contact SPS and give them the dimensions and style of bolt you received, and I'm sure they'd be more than happy to elaborate on what identifiable markings they put on them from the factory.
Just because they aren't ARP, does not mean they're garbage. ARP has just become a household name for quality fasters, and rightly so. But it's not like they have a magic nut n' bolt factory that makes stuff at a higher tensile strength than everyone else in the world.
thank you all for the input does anyone know why they dont have the dimple on the end arp and hpx all have the dimple its some sort of pressure test i ve been told i have been shown old sps bolts that have the dimple i will be contacting sps to find out
ps their from www.stefs.com under specials or type in sps in ebay