That was DPA

Hi,
I'm Steve. I read that u have perkins 4.107 cav bpa hydraulic fuel injection pump information. I'm helping my buddy I'm going to repair his pump replace hydraulic head re seal. I'm a master diesel mechanic worked in Caterpillar dealer fuel shop & have repaired many different pumps but never a hydraulic head pump. This is obviously a marine engine lol perkins not westerbeke. Any info will b greatly appreciated. If u need any more info let me know. Thank you