I want to say I’m new to posting on the forum but I’ve done a good bit of browsing trying to figure out my issue. I have a 1984 4wd pickup brand new motor with 1600 miles. My issue is between 15-1800 rpm’s the motors starts to cut out and backfire. I jetted the main carb jets (primary and secondary) thinking it may be running very lean. I’m now fairly confident that it is atleast getting enough fuel. The first 1500 miles motor ran like a top from idle up to 4k rpm’s (never took it higher) it started cutting at 3500 rpm’s but was drivable and now it’s down to around 1600 rpm’s. This is what I’ve done to it so far. It has a brand new Weber 32/36, distributor, wires, plugs, coil. Ignition and cam timing are both on. No vacuum leaks have checked with unlit propane torch and starting fluid. And compression is 170 in all 4 cylinders. I have also tried a fuel regulator trying every psi between 1-8 and I know it’s supposed to be 2.5psi. From what I understand a Weber 32/36 cfm would only support a 1600cc motor with a 22r being 2400cc could that be my issue??? Makes no sense because lots of guy including my buddy’s run that carb. Thank you for the help this has been confusing me and everyone I’ve asked about it.