apache

I recently contacted the rebulider of my injector pump from my 93 and was hoping to pick his brain to see about where he had set it so I can set up my other 93, 350 pump the same.Man it runs good. He told me that all the mods were internal and by me adjusting it as most do I could not acomplish the same results. Sound like a tale or? What is done internally to up it and strenghten it? I tried to convince him after the last one I took him, if he tells, I will set it, and shortly after it will end up like the first one with him rebuilding it, so it will be more buisness for him but no dice.
Any opinions on this?