header bolt size issue

[IROCdan330]

I want some Stage 8 locking header bolts this time around...as the ARP studs didnt work out due to clearance issues around the primaries (the nuts were too big). I dont know whether to get the 3/4" long ones or the 1" long ones. If it helps, hooker 2055 headers and vortec heads.

http://www.thunderracing.com/catalog/?action=vshop&vid=6&pcid=54

[The Fixer]

You'll probably need the 1" long ones, especially if the header flanges are thick. Can you measure how deep the the heads are threaded?