Inspection of new parts:
Though I was super excited about the new parts but closer inspection revealed some differences when compared to the original parts. This mater has been highlighted in post #28.
The old/new parts variations WRT valves are:
Both the new inlet and outlet valves are thinner. The difference between them can be seen.
I have taken the mater up with the engineering company and this is their reply:
"The valve heads are thinner than the original ones because they are made of a superior material including suitable for unleaded petrol, therefore they do not need to be as thick as the original ones. Also they are lighter in weight resulting in less strain on the valve gear."
So we can say that this is an improved design based on better materials and modern fuels.
Differences WRT to guides:
Inlet original guides are cast iron 64mm long and the exhaust guides are Phosphor-Bronze 77mm long. While in the case of the new ones, both inlet and exhaust guides are Phosphor-Bronze 77mm long.
Manufacturer's reply at this deviation is:
"The valve guides have been standardized. Bronze is a superior material than cast iron and is now necessary as it is compatible with the material from which the valves are now made. They are all 77mm long for production/cost reasons. If it is necessary or desirable the inlet guides can be reduced in length."
I will not be reducing the length of the inlet guides as the additional length does no harm. In fact the longer guides will provide more surface area to the valve stem in the way of support.