New build.
 

Where to start first?
Mount engine?
Stinget and stuff tube?

Going to depend (to some extent) on what you are starting with.

Realistically you should lay out the boat - figure the best location for the motor/s keeping the balance of the boat in mind (for most boats it is ideally the finished build should weight balance between 25 and 35% from the transom of the boat). Also determine where you will be mounting radio box (and the servo layout needed), fuel tank, exhaust, Air scoops and air flow, floatation (in the hull and under the hatch), transom hardware. Personally I have not got a particular order I use when doing a build. Some things make more sense than others. Realistically the transom hardware and the motor should be installed before other components as they don't have much flexibility on where they should be.

Post some pics of what you are building!

I'm In Australia and waiting for parts to arrive from the states that will prob take forever with everything going on, but as soon as I start I'll for sure post some cause undoubtedly ill be asking more questions...

Where in OZ? I spent the first half of my life there (Mostly Gosford) before moving to the US.

One place that I have found has very respectable pricing and great service is hobbysupplies.com.au. Tonys site is on my top 5 whenever I shop.

I have uploaded a bunch of build pics that I got of some nice builds in Germany (mostly) that may give you some ideas on how things can be done. Never hurts to get some inspiration. https://imageevent.com/justaddwata/m...ipsfromgermany

Um, Guys, you're all giving answers for a vee hull. How do you know he's not building a hydro? The first thing I would have asked is what kind of boat he is building.

Sorry, it's a Delta force mono. Df90 mk2.

No need to apologize since everything is good. It's just that I've seen many times where someone asks a question and the answers given just assumed the R/C being asked about was one thing or another and, many times, the answers given were for something different than what the person had. In this case, all is good so I can find a pillow and go to sleep.

hard to mount a stinger on a Hydro or cat!!

And I would agree BUT, with that said, I do know of some that refer to a strut with an extended length tube as a stinger. I was told by someone a while back that this was a "stinger":
Attachment 2270044
Now, granted, you and I would call that a strut but someone that's new to the hobby might hear someone talking about a stinger and think it's a universal name for anything that houses a stub shaft. Experience has shown me that does happen

​​​​​​All good, I have an adjustable cc racing stinger.