I am using mercruiser power steering mount #806394A1. The used chrome power steering pump that I bought won't align with the crank pulleys

can you post a pic of the pump ?

That is correct the spring and pressure relief valve are of higher pressures compared to what GM auto / truck side use for the Saginaw units.. After changing the spring and pressure relief valve, it is very wise to verify the pressures and follow all the testing procedures that is all described in the Merc OEM service manuals. Merc sell the tools to do so. I actually have 2 sets.

I actually started to sell a filter for the low pressure side of the steering system. If you ever took a sample deep down in the corners of the reservoir a lot of times its crud that has settled. Sometimes even corrosion.

Thru out the years Older units were different with the reservoirs and some components. .

Can the correct spring and pressure relief valve be verified visually from the incorrect GM Saginaw parts?

also the hole dia in the nut needs to be a specific size for hyd steering they say, most need to be drilled

I had the same question years ago and did the following:
http://www.offshoreonly.com/forums/d...-16792a39.html

What pressures and flow are suitable for standard marine power steering, and external single/twin cylinder rams?

Also, does anyone know the difference on the relief valve and spring on auto/marine pumps? Is it something you can visually see?

It's pretty much just like a relief spring setup on an engine oil pump. Stiffer springs will have higher PS Pump pressures.

Thanks, but I was looking for a picture with side by side comparison pointing out the differences, if they can be seen. Something like orifice size and location and on the fitting, and maybe spring color, uninstalled length and/or number of coils. When you lay two different engine oil pump springs on the bench, there is a noticeable difference.