Hemavol is a stimulant free product so you can take them together, no problem.
Pump HD contains a lot of stimulants so start with a haft serving to access your tolerance.
However, as everyone posted above - that is a very expensive stack and there are much better options. I like 3 pills of D-spark from n2bm.com + a b100 vitamin + a small cup of black coffee as my pre workout.