Automotive Steering Pump VS Marine

[Stillrunning]

I have a 1999 350 GM 5.7 Mercruiser. My pump has a pin hole and a marine pump is around $500. After I recovered from shock I started looking at an automotive pump. They look the same except how the smaller hose clamps on but we can work with that. I can get a re-man pump for $60. Anyone know if there is any difference in these pumps or a reason to go with a marine vs automotive?