Those little O-rings SUCK. They make some little boots not that wrap all the way around the ends of the tube and insert into the holes in the float bowls. Why the worry about removing the carburetor? It's a ten minute or less job.
Here are the seals. They seal WAY better than those O-rings ever did.
Holley Carburetor Carb Transfer Tube Rubber Seal O-ring 2 PACK HOL-108-97 A58 | eBay
