[HO455]

Here is another tip for your headers. Most headers are not ground flat and true on the sealing surface so the bolts will never pull them down to seal. I always take my headers and true them up on a large belt sander. This gets all the contact surfaces in the same plane. With your six cylinder headers you may need to find someone with a four foot sander. They are common in cabinet shops, but cabinet makers are NOT real fond of sparks. It can be done with a straight edge and a surface grinder, it just takes longer, but it is well worth it. I had a set of AMC headers that were so far out I ended up having to weld more material on the face to get a uniform sealing surface. Hope this helps.