I have Tom Langdon's twin progressive weber two-barrel carbs on my Chevy 3600 with a 235, and the Fenton twin carb intake. I also have Fenton split exhaust manifold. I ran hot water to the intake. I re-jetted the primary (smaller idle and main jets) on the weber carbs to my expertise. I have the 6848 head. I have NO dead spots when the engine is cold, it accelerates very well, no lack of power at any speed, I have the SM420 four speed, Gearvenders Over drive and a 4:10 rear end out of a 71 C20 Eaton. It gives me a final of 3.2:1 ratio. Hills are No problem, I can run with normal traffic, and I have gotten as high as 20MPG highway and 15MPG around town. 55mph is 2100rpm and 60mph is 2300rpm. I have the stock cam with NOS hydraulic lifters. It starts instantly at a dead idle, runs quiet and sounds awesome with the dual exhaust all the way back to the rear bumper. Did I need to do this? No, but I enjoy a project that challenges me. My automotive machinist friend who has worked on these engines many decades ago said they used to do all kinds of improvements to the 235 like I did to mine. I could not be happier with my truck.
