Yea the 5vz-fe is like that as well...stock lift is around .330" and i now have them sitting at .370" coil bind aint far off. The guys who make the valve springs are amazed people are not killing their engines because of how soft the springs are.
The new valve springs have a much greater coil bind level and increase in pressure as well for all sorts of engine builds
As for flow rates...I agree that if you port and polish the hell out of the head and keep the stock lift/duration cams you will not see a gain as the cam truley is the doorway into the combustion chamber and if you do not allow enough time for the air to get in or out then whats the point of having that huge highway for the air to flow when there is a tiny doorway
Hence why i notice a large improvment with these engines (the VZ's mostley) when just a simple cam upgrade is put in. NOW the test i would love to see is at a greater lift and stock ports vs mild port that is what i hope to test in the future.
As for the valves, i agree 100% that going with a larger head will not yield good results at all plus it would be very risky to have the head cut for those larger valves anyway. That is why i decided to bring out the high flo line as the valve is the stock size but just the area above the head is reshaped to allow for a greater airflow and it has worked very well with the 2jz crowd as well. I will be doing more tests with the valves in the future but i cant see how these cannot benefit most users, we shall see! I am building a stock block 5vz-fe with my modified valves, cams & valve springs to see what kind of power i can get N/A with stock intake manifold.
As for the 5vz-fe builds i do here..the only current "porting" is just a simple clean up