The 74123 and the CD4528 are not compatibile but they are both timers and can do almost the same jobs ..
For example, if you decide to use the 1/2 CD4528, connect input B to +V (also control input C has to be connected to +V) and connect input signal to the input A ..
Each time the A-input will find a rising edge of the input signal, regardless of the length of the input pulse, the output pulse will be the same - 1ms, for instance - and will be detetermined by the external Rx and Cx (see data sheet at: **broken link removed**) ..
Rx=100kΩ and Cx=47nF should generate output pulse pretty close to 1ms ..
The pulse's length is almost independent of the power supply voltage, so if you have 12V or 15V or 5v it really doesn't matter ..