John,
I found the rest of my notes about my 34 mm Dellorto carbs. They have the same AB265 needle jet you are using, but K3 needles. As originally set up, the carbs came with 60 slides, K3 needles, AB265 needle jet, 145 main jet, and 70 pilot jet. My first race with them was at Daytona, and I had to drop the needle down to the top groove to get it to stop blubbering badly on acceleration. It would run ok once it got to 6000 or so, but would barely run on open throttle below that. After I changed the pilot to a 65 and raised the needle backup to the middle groove, it ran much better. Trimming the slide down to about a 54 cutaway really helped the low speed response, and I eventually worked down to smaller main jets, and that's pretty much where it's been for the last couple decades.
In my previous post, I said the slide was between a 40 and 50 cutaway, but it's actually between a 50 and 60 cutaway. Sorry for the confusion. I've edited the post to correct it. You mentioned that you had a "40 slide, that I had machined to 55". I'm guessing you meant a 60 slide cut down to a 55, which is really close to what I've been using.
Ken