Frank,
When I was looking to find a replacement, I found alleged NOS Carter YFs online for about $240.00 a piece. It may be worth doing a search and asking on the stud spacing.
In general, single barrel carbs are very difficult to find these days. I even went to the local speed shop and they couldn't get anything less than a 2bbl.
Again, I found a Holley that might work out through a local Autozone. It was too wide for my stud spacing.
Good luck. I am, for obvious reasons, a bit biased when it comes to 39 trucks.
