on my 428 in my '69 F100.
Since everyone is out of gasket kits lately for just about every Holley, I dug out the converted 735's(single feeds) I built last year for the wagon. I tried them once on the wagon, but they needed more tuning to actually see an improvement ET wise(they were a bit fat on the top end). I decided to try them on the truck just so I could drive it without the constant flooding out when you shut it off.
WOW, those are snappy! I'm guessing it's the step boosters that really kick the response signal up compared to the 1850's(one reason I didn't like them on the wagon). I only went around the block last night, but I like it. Still a couple things to button up(like make rods for the air cleaner lid nuts), but these don't leak down when you shut it off, so that's a check mark in the WIN column.
For the life of me I don't know where the fuel is coming from on those 1850. I've never had such issues with a Holley carb. That rear one was leaking externally pretty bad down the intake and puddling up. Likely from the throttle shafts from when it drowns itself when you shut it off? Front carb area was always dry. I have a few Holley books, but I need to really read up on them to see just what EVERY channel does and why.