[Gordo2]

I don't recall trying the F11's, however at a glance (without looking at specs) - they appear to be very similar to F16's.

My carbs came with the F16's E-tubes - which seems to be Mr. Parr's (PMO) go-to E-tubes because they seem to work well in most applications.

I tried the F8's because I wanted the transition from idle/progression to mains to begin at a lower RPM (my engine was going lean during idle/progression transition to mains). I was battling a hesitation problem that was due to leaning ~ 2.5 - 3k RPM.

The F8's definitely promoted a lower RPM transition to mains, but also resulted the mixture becoming very rich across the entire main circuit (3k & up RPM's). I could have corrected this using different main and main air corrector jets, but I was pretty close to getting to a good point using the F16's with the main and main air corrector jets that I had available. As such, I ended up optimizing using the F16's E-tubes.

I found that the 36 vents (vs 38's) also promoted greater vacuum at lower RPM, therefore drawing more fuel/air, which also helped offset my idle/main transition hesitation issue.

Keep in mind - the engine's camshafts have a significant influence on carburetor's required settings / jetting. My setup was tailored (via a studied trial and error process) to match the requirements of my cams (DC's - GT2-102 with a "carb friendly lobe").

Good luck - enjoy the learning curve.

Gordo