Wow, things like what you are going through with the political virus makes me feel bad for folks that don't have the freedom that us Americans take for granted.
Looking at that head, reminded me of when I built a Frankenstein Z series for my 1980 200SX (think it was the Silvia for you folks, was the hatchback and that was the model name for the Japanese market). I used the Z24 block from a pickup and because the car was port injected rather than carbureted, used the head from an 1983 200SX (they came with the Z22 here). The intake ports were a different shape, more oval with a notch at the top for the injector to spray into. Also had slightly larger valves than the original Z20 the car had. That combination even with the dished pistons that I accidentally ordered (I thought I was ordering flat-tops) was enough to bump the compression to where I had to run premium gasoline during the heat of summer. Also wound up using the flywheel and clutch I had for my 1975 280z (left hand drive Fairlady for you folks ) since the Z20 clutch was too weak and the new clutch was slipping under load from day one.
That little project taught me that rebuilding Nissan engines was expensive compared to the common American engines of the time. Looking back, that project was 25 years ago, man I am old....
Hope things blow over soon and you can get back to real life again.