Yes it looks blown between 2 & 3. Does not mean the head is warped. I've changed A-series blown gaskets without planing the head and they were fine. (First check for warpage). Block prep is the key: get it clean, no oil on the faces, and tighten the correct pattern, 3-steps, correct torque for the '13' bolts. If you have the original bolts, replace them with a good used set of newer bolts. Re-torque every two years per the Datsun schedule. She'll last forever.

If you are trying to win a race, you may wish to blueprint the engine closer than the Datsun spec of 0.004 allowable warpage.