Hi Andvil.
What bomb do you have? There are individuals, that is, a pump for each cylinder, in that case you have to refer to the wheel and put it in the degrees that you want the pump to open and then remove or put on the pump until matching the marks it brings. If it is rotating there are marks in the pump housing and in the motor block just at the assembly site, there you can synchronize the degrees you want. If it is a pump with your own tree (APD) you must put the degrees you need and move the gear to the point you want.
Luck.
Miguel