OK.
I'll bite.
The why is to give a proper response.
My question then is, what's the bore difference between the two?
If its the same, you gain nothing other then reworking linkage and possibly lines. If their diffrent you effect travel and force.
I built one of those out of an old stainless water/fire extinguisher. I put white lithium grease in the pump gears to prime and force oil through everything with the extinguisher.
The Summit racing one is way nicer then mine.