[TommyPettigrew3076]

Are you sure it isn't an exhaust leak ? These motors are known to for the manifold bolts to break of mostly on the very back . I had this same problem chased it lifters , flushed , different oils turns out that is what it is they even make a kit to fix the problem I found through a buddy of mine that had the same problem I will try and find the

linkhttp://kralautoparts.com/product/exhaust-manifold-bolt-repair-kit-kap169