M35B alternator replacement

[MarknCat]

Hi all, I have a 2000 M35B and what I assume the be the original alternator is only putting out 12.6V so it's time for an upgrade.

My electrical system is a dedicated and isolated AGM start battery in the closet aft of the chart table that is charged by the alternator (and an aux 110V smart charger on shore power), a 30A Victron DC/DC that when the start batt is full feeds the bus that's connected to my 300AH of LifPo house bank. I also have 150 W of solar that feeds the house bus and a Renogy 2000W inverter/charger that manages shore power and connects to the house bus.

I decided to go with the L/N 110-603 90a alternator even though my peak load is only about 45A (30A for the DC/DC and 15A for house loads if fridge is running and tablets charging, etc), so I have some headroom on the alternator. I'll stay with the internal regulator for now. I am happy for feedback on this plan.

I have done a BUNCH of reading on the site but still have a few questions:
1) Will I need to replace my pulley?
2) What's the best way to get around the water hose? And will I need to bleed the cooling system after?
3) What's the best way to test for belt alignment?
4) If I do need to adjust alignment, is there a better way to do it that just washers as shims?

It seems I have a lot of belt dust on the engine, and the belt looks a little crooked to me (pics below).

Thanks!!

Mark

[KWKloeber]

Are speaking about the seawater pump hose?

It appears that someone added a fitting and routed it differently than Westerbeke -- OEM, it runs aft between the Alt and the engine so that you don't need to remove the hose in order to change the belt.

It's hard to tell about her Alt alignment w/o a photo perfectly straight down onto the pump/alt, instead of at an angle. 
How to check the alignment of the Alt is generally to clamp a straightedge against the pully and measure.  Mainesail shows how to do it on his website and there are photos of how to do it on this forum. 
https://c34.org/bbs/index.php?topic=9380.15

The belt would benefit from a billet machined alternator pulley and I would do it anyway since you are going to a higher amp.