i ordered a set of them from jegs last year and when i got them only half of them were long enough to fit. the top 3 on each side werent long enough to compensate for the holes on the top header flanges. i had to call arp and get six different studs that were long enough. they were 1 3/4 inch long if i remember correctly. not sure if the kit will work with stock headers, but i have postons headers and had to go this route.
buickbert