Thanks for the interest.  I found an all-aluminum $200 5.3 LS4 out of a MonteCarloSS, so that is my current plan.
Life has really prevented this boat getting done so far, but have new shop now and it needs to get done.
I'm wondering how to get the water cooled exhaust for the LS and hoping I can use the 455 manifolds I have.

Wow, can't believe I started this project in 2014, so it has been 10 years now!  And I still have the boat and it still doesn't have an engine in it.
I am determined to get it working for the spring of 2025.  Was even hoping to get it working this month, but the Ford 3.8 V6 I picked up to use turned out to have no compression in 3 cylinder and had bad valve guides. They are 200hp and compact and light.  But no time to fix it.

My current plan is to put in a W8 engine from a Passat I picked up years ago.  It was for a Porsche 914 project, but I have sold that car,
and can't think of anything else I can put this engine in.  Being they are at this point very rare engines with no parts available, seems ideal for a boat that is not run many hours a year, so it should last a long time.  And they look awesome with the big fat cylinder heads and had a great F1 kind of v8 sound.  275hp.

I am thinking of two different issues.  The first is the coupling from the jet to the flywheel.  I have a u-joint coupler that came with the jet.  It seems it is very heavy duty. I want to move the engine further back and the "driveshaft" moves the engine forward a good amount.
I am familiar with jetski's couplers, they are much more compact.  Was thinking maybe they can't handle the power, but I looked at the newer yamaha ski's with 300hp and they use the same style of couplers.  The other idea is to use the driveshaft coupler used in a BMW, 
Any input on these ideas appreciated.

The other thing is I want to eliminte the alternator and starter on the engine, and replace it with a single motor like a hybrid system does.
I have the generator motor from a prius and am looking into attaching it on the jet input, so make the coupler on the jet side also a motor/generator, that can spin the motor to start it and also work as an alternator.  And it could also add power on takeoff for a short time.

Anyways, it may be I can't get going on this until next year, but I've got the boat all cleaned up and can do some work on it now.

That will be a tough repair.  I think you are right to consider making a mold and get a whole new section to replace the damaged area.   I don't see how you can use the other side of the boat.   I'd try to find another good identical boat,
and make a mold off it and them make the repair section from the mold.   It won't harm the boat to make a mold if done right.    Replacing the hull is certainly a better bet for a good outcome.
You can do it the 'hard way', it will be very time consuming doing all the shaping and sanding to get it right without the replacement hull section.  my 2 cents.

Slow progress on this project!
I've been building the twin-turbo 12A rotary engine.  Never built a rotary before, and it took 4 tries to get the seals right,
but finally got it, now holds 14psi in the water jackets.   Still fabricating the twin turbo exhaust manifolds,
here is picture of the early going. 

But have taken a break from the engine work, and wanted to finish the hull repaint.
I've stripped all the stuff from the hull, removed all the decals and sanded it.
Now I need to paint it.   Here is what I'm thinking for the design.  Basically going orange black and white as the theme.
Got some nice burnt orange vinyl to accent my seats that I will be making.

Yeah, heat exchanger might be the best approach, can make the jet water without any small openings
so it won't clog, though still need some kind of filter I assume.
It will require a water pump for the engine, the 12a pump is one big heavy cast-iron pump
that I was looking forward to getting rid of.  Maybe I can setup an electric one instead?
Don't want to run a belt on the engine.
The plan is to combine the alternator and starter with a brushless motor (no sparks)
direct coupled to the front shaft

What is needed to paint the Berkeley Jet? 
I've seen one or two painted, it looks quite cool, but what is involved?
The white paint is on pretty good, just sand it and paint it??
Is this a good idea, or will it peel?   What kind paint?  2-part and clear?
Thanks, JackB

Cut hole in perfectly good hull, then made that big hole even bigger with a router.
The board to fill it slips into the routed slot. 
It seems from other posts I've found that the pump should not be mounted straight with the keel,
but angled up 5%, that is about what the existing transom angle is close.

Time to get back to this project!
Trying out positioning of the jet.  I assume that I want the ride plate level on the same plane
as the bottom of the hull, is this right?

And as has been pointed out this is an insert jet.  I have not seen any pics of them closeup how
they are installed in OEM configurations, anyone have some pics?
Is it important to be able to remove the jet?  Can it be serviced while still in the boat,
or must it be removed?  Is a press needed to get out the shaft bearings?
Thanks for any help, I have almost no experience with jets, but I will by the end of this project!

I was looking into making a custom tank that would fit in the V under my floor to free up space,
and found that you can make tanks from fiberglass, but you must use vinylester resin, not polyester.

I don't like aluminum tanks because ethanol can eat them up over time, and I like to keep that fuel as an option.
Being able to shape a glass tank to any form can be quite useful.

JackB

On my 15ft boat, I put some rollers (cheap harbor freight wheels without the tires, just rims)
 in the ceiling rafters in my garage, and ran straps around the hull.
Then I could roll it over by myself.  However, I only really put it up around 60-degrees, was enough to work
on the bottom on that side.

JackB