Having developed a knock in the right head of my father's 2.5 GTV6, we decided to pull the valve covers and take a look. What we found was a badly worn valve lobe and tappet. So, at the recommendation of so many, we replaced the cams with those from the 164s. We pulled the heads, did the head gaskets, and through in the new cams. The engine is now back together, and the knock on the right side is gone.
However, we now have a knock occuring in the left side. We've had the cam in and out, checked the clearences, and it all seems good by the numbers.
One more thing, if you apply pressure to the cam cap nut on the face of the cog, the knock goes away completely. Now, we're stumped. Any help would be greatly appreciated, Thankyou