74HC04 Propagation Delay at 3.3 Volts
TI recommends linear interpolation. Other manufactuers appear to be silent.
But even if you had a device (like the (SN)74AHC04) that specifies values for 3.3 V, the min…max range is so wide that you could not predict the actual propagation delay.
To get an adjustable delay, use something like an R-C circuit in front of a Schmitt-trigger buffer.