Did you check the operation of the carb choke. I assume it's a manual choke. On my 1950 3100 w/216 it has a manual throttle cable in addition to the manual choke cable. I had this problem originally, but if I set the choke properly to get it started I then set the manual throttle cable so the engine has enough rpm to keep it running until warmed up. If it won't stay running after it's warmed up, then I would think it's a carb problem. On my 50 I have a single barrell carb, which was very easy to overall and the kit wasn't to expensive. When you have the truck running, hook up a vacuum gauge to one of the ports on the carb to see if you have good vacuum. Don't recall what the vaccum is for your 235. If there's any vacuum leaks then that could contribute to the other carb problems. As mentioned in an above post, be sure to set the carb float properly to insure proper fuel flow. One last thing, although you have spark now, is it a good strong spark? On my 50 I have a braided copper ground strap between the engine and the frame. Initially this was aproblem for me getting spark.
