What is it you should not do on the nose cone install and what prop. did you run?
What I learned on the nosecone install....is to let someone do it who knows what they are doing...lol. When I got it on, I realized that is was a little off, and I had to start over again...not fun!. Also, the backfilling should be left to a trained professional- it took me FOREVER to get it right.
The best prop I found for top speed was was a Hill 4-blade chopper (Thrasher?)- it had some bow lift, but the best overall prop was a Hill 4-blade Turbo- it had less blowout than all the others I tried (I think I went through 8 props before I got it right). My boat was big and heavy, so it didn't like the three blades- yours might be fine with a three blade.
I have a 24" Ultra LH and a 24" Ultra RH. I have a port helm so I will run the LH prop. My drive is about 1 1/2" lower than the bottom of the transome. I can move it up 1" or so. I may just have the bottom glassed if that is possible since I have a pad that is 12" wide at the back and runs forward about 5'-6'. My boat is an 1980 Kona mini daycrusier that was more or less designed for a jet drive. Any suggestions?
You should stay LH because RH will put the torque on the lower (smaller) gears. All V8 and Diesel applications with these drives came stock with a LH rotation for this reason- the drive is stronger LH rotation.
Like your boat, mine also had a pad. Many builders back then were doing the same hull for jets or I/O. For an I/O, they simply put an insert in the transom, and beefed it up with thicker wood. The problem is that with such a shallow V, the drive sits very deep in the water by today's standards. If you really want to make your boat go faster, you'll need to raise the "X" as far as you can...but that may be limited by how high you can mount the motor.
There was a guy on OSO a few years back that was modifying Bravos to shorties by cutting the lower and shortening the vertical shaft. A few hundered bucks and you'd have yourself a higher "X" dimension!
If I was really going to "hot rod" my 290, I was going to either do that, or, buy an old Duoprop lower and have it shortened and bolt it on (they are interchangeable). I would have had the first "Volvo Surface drive" (like a Merc Blackhawk). However, I sold the boat before I went down that path.
What kind of boat is that, and how big?
I am curious what your top speed was in that set up. I realize that the steering doesn't change the top speed, but I do not feel comfortable topping approx. 65-70 without hydraulic steering for safety reasons alone.
The boat was a 23' Daycruiser- it was a big, heavy boat with a small block, so I think the best I got was 65 MPH. Like you, I didn't have alot of confidence in the Volvo steering (as a kid, I was once in a boat that had the steering break- not fun). The external setup solved that...I couldn't wiggle that drive AT ALL when it was done. Before, there was a couple inches of play in it.
There are only two real issues that I found with these drives:
1. Getting parts on outdated drives is sometimes a PITA. It was always an adventure trying to track stuff down.
2. High performance parts are non-existant. Things like steering, shorties, stand-off boxes, drive showers all have to be fabricated.
Having said that, it is very expensive to convert a boat over to another drive (Merc, Arneson, etc.). Sometimes, it's worth it to play the cards your dealt rather than buy a new deck.