I ran dual rods, yf's and glass bowl hollys on my 235 motors (and triples on an offy intake) for quite a few years until I swapped over to a pair of Holly/Weber 5200s from a 74 pinto. (progressive 2bbls, I used the 74 version because the inlet is threaded as opposed to a pressed in brass nipple for the earler modles). I used adapters on a vintage Weiand intake. The difference in the way the motor ran was significant. Ran way better on the 5200's. When I installed a 261 in 2015, used that same set up. Ran pretty good. Then I decided to step up to a new Clifford 2X2 intake using a pair of 38 dgev webers (same basic carb, just non-progressive and larger). A big difference, a really big difference. I don't think I could have realized any real gains by just using the 38 mm webers on adapters and the Weiand. Although I loved the Weiand, and had run it for many many years, the clifford was so much better in terms of performance. So yes, I think direct to plenum has its advantages over adapters but I also don't think there is necessarily that much advantage if all you are doing in running a mild built 235 on the street. If that is what you are doing, head to the 5200s on a traditional vintage intake with adapters.
