I recently bought a 76 f250 super cab with a 460. The truck ran ok in town but when I got it on the highway it flooded out and died. The air filter was clogged so I figured that was it. I replaced it and it ran fine for a few trips then it happened again today twice when I gave it more gas. Both times when I removed the top of the breather it fired right up. I was thinkin it could be bad gas but why would it start without the breather? Any ideas?