FWIW, I have had good luck with replacing the Rochester B/BCs due to recurring leak/warpage issues with the Chevy-spec code 14-xx Stromberg carburetors (BXDV-3 or BXV-3s) on 235s, and using BXOV-2s on the 216s. The nice thing is they have leather accelerator pump seals, so will last better with ethanol (E10) fuel, to Jon G's earlier comments. The Stromberg's pop up regularly on eBay, sometimes well priced, and sometimes at ridiculous prices.
Many times, I've found NOS or old-rebuilt Stromberg carbs at very good prices, just takes some shopping and patience. It's getting much harder to find BXOV-2s that are good and affordable, especially if they are the later 1-5/32 venturi models. Earlier 1-3/32 venturi models are still fairly available.
I have a bit less experience with the older Carter OE carbs, but the W-1s seem pretty bullet proof. The Carter WEs seem viable as an alternative, and I've used some of the fairly common 730s replacement carbs with pretty good results.
