1964 Ford F-250 chokes only in 4th gear?
I recently got my great grandpa's 1964 Ford F-250 running. A few months of driving I was on the highway when it choked and sputtered like a clogged fuel filter. I pulled it home and after a few hours was able to drive it again. This happened again later and it only happens in 4th gear. If I stay in 1 2 or 3rd gear I can drive forever but as soon as I shift it starts to cough and sputter out. Any ideas?