The Carter-Weber progressive 2-barrel carburetors (sold by Tom Langdon) can easily be bolted onto a 2-carb manifold by using the
common/standard 2-barrel to 1-barrel adapter (@$15 with gaskets/bolts). These carbs seem well-suited for a 235.
I get 18 mpg (on a 261 w/3.55 rear-end) at 60 mph and 12-14 mph at 65-70mph. This has been the smoothest, most reliable carb set-up that I have used (comparing to a few other one or two carb set-ups).
The only negative I see is that they do not look "old school" - they are only a 30-year old design. I have adapted oil-bath-to paper-filter 1950s air cleaners on them (gives them a little older character).
