The Carter YF has a "ported vacuum" connection near the base of the carb, and I believe it doesn't become active until the throttle plate is just off idle. At least that's what I've observed with my Carter YF setup. I believe the hard line to the distributor is smaller than 3/16" OD. It doesn't need to be that big.


Kevin
1951 Chevy 3100 work truck
Follow this saga in Project Journal
Photos
1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car)
Busting rust since the mid-60's
If you're smart enough to take it apart, you darn well better be smart enough to put it back together.