3120xp Sprocket Questions

[forcemac]

I am trying to avoid another boneheaded mistake (see previous thread mounting holes for bar tightener) and thought I'd ask the pros here.

I am thinking about a new saw for my 36" alaskan.  I originally had my eye on a 395xp because I can get one with a stock 3/8" sprockets and would work with the 36" bar and 3/8 rip chain I have (bar is a Granberg 36").  However, I do envision myself going up to a 60" or 72" alaskan mill sometime in the future to do some oversized stuff and the 3120xp will be what I need for that later down the road.  

So I am thinking of just going straight to the 3120xp for the 36" mill instead of a 395xp.  But I believe I cant use my bar/chain without some adaptation on a new stock 3120xp 

That said, as far as I can gather, the 3120xp now only comes in .404.  At some point it must have come in both 3/8 and .404 flavors because I see threads and parts mentioning 3/8 dimensions.  

Question 1) So, if i went with a new 3120xp, I assume it comes in .404 as the 2021 catalog indicates the 3/8 does not appear to be an option...can anyone confirm this is the case?  

If .404 is the only flavor now....I would either need a) completely new 36" bar and rip chain; or b) or a 3/8 sprocket to go with my 36" bar and chain.

Question 2) From my research, it appears that an Oregon 68210 sprocket is what I need to convert from .404 to 3/8.  Can the community confirm the 3120xp comes with rim sprockets as standard and I do not need the whole assembly (as in converting from spur to rim?)   

These are my references:
https://www.outdoorking.com/pages/Oregon/Oregon%20sprocket%20reference.pdf
Rim Sprocket, 3/8" | Oregon Products

The prospect of me removing the clutch on a new saw is not ideal in my newbie mind, but seems do-able from what I can learn from youtube...although there seems to be some variation in the need for a piston stop...some guys do it, some don't.  

Question 3) What is the pitfall of not stopping up the piston when hammering on the clutch to loosen?

[Upstatewoodchuc]

You can put whatever sprocket and bar combo that has a d009 mount on you want. I use my 3120xp with a 36" 3/8 bar for quartering big firewood chunks and I use it with a 72" cannon bar in .404 for milling slabs.

[Guydreads]

The piston stop, which can be a simple piece of rope, is going to make it a whole lot easier to take the clutch off, as the motor won't be able to stop the crankshaft from turning over as easily as a piston stop if used properly.