I'm currently out in the driveway replacing the manifolds on my '04 Ram 4.7L with Gibson headers and my father and I can't figure out what size bolts are in the manifolds? We got the first stud out but the rest are the smaller ones - Something like smaller than 5/16"-ish... Clearly, it's not good to round these bolt heads.
Engine: 1998-2001 360ci (5.9L) Magnum V8 245hp(standard), 250hp(Sport package)
Rep Power: 21
I'm not sure . I just had a set of 4.7 heads here that I disposed of . If you think their 5/16 , if their coarse thread they should be 5/16-18 , fine thread 5/16-24 . Now be careful because 8mm is real close to 5/16 .