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Cefiar
The only issue I see is that with all the specs I've seen on all HC/AC/HCT/ACT, logic "High" is considered anything from 0.5x (typical) to 0.7x VCC (the guaranteed limit at the temp specs of the package - -40C to +85C). At 5V, that means between 2.5v (typ) <-> 3.5v (max). This means as long as we're within the typical window (which never seems to be 100% defined on these things) we should be OK.
What you say is true for AC/HC but not ACT/HCT. The VIH threshold for HCT is 2V. You can read that in any datasheet for an HCT part, so I don't what specs you were reading.