John,
Sorry to disagree, but that tinware under the manifold serves an important purpose. It keeps the hot
oil off the bottom of the intake. The purpose of that being to reduce heat to the intake charge, which in turn makes more power, makes hot starts easier and helps prevent percolation in the carburetor.
Other than this, I would add that it is far better to back the rockers off before removing the assembly. Yes it is much easier to just unbolt the assembly, but, no matter how it is done, there is a real risk of bending pushrods when re-assembling....especially if high valve spring pressure is present.
If the heads are aluminum, it is also very easy to strip the threads for the rocker stand bolts doing the bolt back without releasing rockers. This is because you will begin to put high loads on the bolts with very little thread actually in the head. This situation can also occur with iron heads.
A good rule is to use thread sealer on all of the rocker stand bolts.
While I'm at it, if not already done, when the rocker assemblies are off is a very good time to put in an
oil restrictor.
Look at the center bolt hole. You will see a concave depression with a hole in it. That is the
oil supply to the rockers. Find a piece of mild steel rod that fits the hole snugly. I think it's 1/4" but not sure anymore. Cut the rod so it fits flush with the bottom of the depression when inserted in the hole. Next, drill a .060" hole through the length of the rod and insert it back in the hole. Obviously the hole should be centered in the rod as best you can. Do this for both heads. The oil supply is now still ample for good lubrication, but not excessive.
Advantage: Keeps oil in the bearings where it is needed instead of pooling in the valve covers.
Al