Did you get this finished and running yet? Planning to do the same thing and just wondering how this turned out.

I did but I have only run it on the hose, the boat hasn't been back in the water yet. The pump seems to move a lot of water and fills the raw water side quickly. One thing I've noticed... even with alignment being as close as possible on the crank (I don't see how it could be aligned any closer), there is still a very small amount of wobble that I need to correct. The support bracket may help... I'm going to add in the spring.

Any specific questions?

the pump housing always moves around a bit i use the 2 hoses to keep it from turning i have found the support bracket almost always cracks or beats the rubber bushing out then making a rattling noise if you have to much pressure there are different cams for the pump a half cam will mellow it out you can run the reinforced hose on the intake side if you want and can make the bends

Yep, reinforced hoses are in place in and out. I was a little concerned about harmonics from the wobble/vibration making it to the rotating assembly. If they all do it a little, there’s probably not a lot to be concerned about and I’ll just leave it.

Water flow is great and I’m seeing a little pressure on the raw water side when running on the hose. A blip of the throttle will give me 10 lbs (never had that with the Merc pump). I’m closed cooled so pressure shouldn’t be an issue.

That's great to hear. I'm wondering if the spacer is absolutely necessary. Would it fit without it? Is it to clear the pulley or just give some extra room. I have to admit that relying on the hose to stop the rotational force makes me uneasy considering if that hose fails, the boat sinks. Is that a legit concern or an unfounded fear? I know they are RUGGED hoses after changing out my fuel fill hose that literally lifted the boat off the trailer before coming out, but still....

The spacer gives you enough room to work with the hoses. On older engines that have a cast crank pulley, the pump is spaced out about the same and aligned to the crank. There’s no option like this for the smooth stamped serpentine pulley hence the spacer and alignment bushings.

Do not worry about the hoses. I replaced 20 year old bilge hoses that were still in good shape. You won’t have trouble there. If you’re concerned about it, install sea cocks.

I have 2 I’ll be I staking also. Tks for the thread. I was a lil curious about myself and was going look into making some type of different brackets/support. Only real downfall I could see.

The fact that I no longer have to cuss every time an issue comes up about a bad impeller in more than enough reward. It really simplified everything for my set-up.

Same for me. To change the impeller I have to remove at least one battery and wrestle the hole pump out. Belt off. Etc. This will be so much easier. This is a maintenance item, preferably a yearly one. For mercruiser to make it such a pain to do was just bad engineering.

Yes, bad design in my opinion, too.

And impellers should last longer than just a season. I've run two seasons but that's about as long as I'd want to go without water pressure gauges to watch for degradation.