OS FS 70. Surpass Part 2/3 Assembly

This engine is still new and I decided therefore not to disturb the valves but then before assembly decided to remove them to clean the valve stems. Before disassembly, the engine was not turning and therefore I just assumed the valves will still seal properly because the engine looked like it doesn't have a lot of run time.
There was no visible damage to the valves and I didn't touch the seats.
After assembly, they sealed and worked perfectly.
I replaced all the O rings and made a new intake manifold gasket.
Now for the test run.