This Summer I was tuning with the different float levels. I started the Summer with both floats at the bottom of the sight glasses. I was able to achieve a real constant A/F range from In Gear Idle to about 65mph and I was happy with it. But I found a problem when I started testing my WOT A/F. 50mph to WOT was not bad, but idle to WOT sent my A/F gauges into the upper 14's and I had to let off.
I kept getting the carb leaning out on the top end so I started changing secondary jets with no real change. Then I started changing HSAB's with no real change. Then I decided to move the floats from the bottom to the mid line and my problem stopped. Now I could control the A/F better on the top end. So that problem was solved but my cruising A/F numbers went way rich on me so I had to start over again with my Idle In Drive to 65mph cruising A/F's. I knew that the float levels changed the curve of the entire carb range but this showed me exactly what that meant.
When I had the floats at the bottom, I used richer IAB's (.060's) to get the cruising A/F's where I was happy. Then when I raised the floats, I knew that I had to change the IAB's so I leaned them out a little at a time. I used (Front/Rear) .060/.060, .065/.060, .065/.065, .067/.065, .067/.067, .071/.067, then I ended up with the .071's front and back. After each change I wrote down my In D A/F plus 40/45/50/55/60/65mph readings. I also tested with different Main HSAB's to try to bring the numbers down doo. I tried to do these tests with the outside weather within reason to keep the tests accurate.

This morning I test drove with the latest changes with the best results. I now have the same results that I had back earlier in the year when the floats were at the bottom of the sight glasses, but with no leaning out issues at WOT.
I am once again happy with these cruising numbers (E10/9.7:1 comp/with Vacuum Advance):
Idle In D: 13.2-13.6
40mph: 14.0
45mph: 14.2
50mph: 14.2
55mph: 14.2
60mph: 13.8
65mph: 13.4
As you can see, my total A/F range goes from 13.4(ish) at idle in D to 13.4 at 65mph. You can see the gradual changes through out the range as the rpms go up. Going with these numbers, it appears that my mains are starting to kick in around the 60mph range. These numbers were obtained with the following carb setup:
64/78 jets, .071" IAB's, .039" HSAB's, .033" IFR's.
My 50mph to WOT A/F numbers are in the low to mid 12's (12.2-12.6 between both A/F gauges) at the shift point.

This shows the affect of the float levels. So when you move your floats around, it will affect the idle and all the way up the carb setup. (I know that allot of you already knew that, but this is for those of us still trying to get the hang of this.)

Once again, I started this thread to learn more about carb tuning and to try and learn why DP carbs were known to be difficult to tune on the street. What I have learned is that I can see why the older DP's got the reputation of being tuff to drive on the street, but these new DP's with adjustable circuits can be very efficient on the street too. Most of the above tests were done with the carb on the Idle/Transition circuit as it appears that my mains do not affect the curve until farther up the rpm range.