My opinion only. The DCOE does not need or like a plenum intake, they are designed to run with individual short runners to the head. Of course you don't HAVE individual PORTS, so it won't work quite like that. The stock intake is a plenum type. The biggest issue is that the 3x weber setup is likely way too much carb for the application. With individual runners and one choke per cylinder the engine can take a lot more CFM, but still the smallest DCOE is a 40mm (dual). A near stock 250 or 292 would work well with just ONE of them, based on CFM alone. You would be spending a lot of money choking THREE of them down to work with the smallest venturies you can find, and that means all the jets need to be replaced too. Hours of trial and error, and money in parts. And still likely suffer from slow intake velocity not allowing them to work well at low and mid rpms. I have not tried them myself on siamese port engines. Just sounds like a hassle to get them streetable. A hopped up 292 might run well with them.
