I'm sure this same thing has been posted a million and one times...And it's just a stab in the dark but 'ere goes. I put a rebuilt 302 in my '68. Ran it out of the car and it ran perfect. Put it in the car, and it ran peerrrfect. I cut the fuel line (back when it had the inline 6 in it) and put a clear plastic inline fuel filter in it. Also rebuilt the carb. Well the other day I took it to sweep it out, and it would turn over fine but wouldn't start and it drained my battery. (had it tested good battery, good charging, good alternator) I had just put a new fuel pump on it and figured that was it. And it did fix it. Went to cruise it to the gas station (10 miles away) and ran fine until the ride back. I had to keep mashing the pedal to keep it from dying. And it died on the side of the road. Had to let it sit for a second before it would start and it kept lunging all the way home. Even with the pedal smashed. So I replaced the carb fuel filter and the inline one, as well as another fuel pump. And brand new points and condenser. Well today I went to drive it and it did the same thing. I did notice that when it would die or shut off, the clear fuel filter would empty out really fast. So I messed with the choke a bit. And then it kept it filled up. Also though, when the choke is opened all the way even after it's warm it kills it almost instantly. Every time. So I messed with the choke, and it sounded good. Took it out of town, and saaaaame thing. When I cruise it around town it's perfect (sometimes, it kinda does even at that speed but not as bad). Drive it at 55-60 for a few minutes and it starts doing it again. So I either have to feather it or mash it to keep it from dying. And when I come to a complete stop or start to slow down, it acts like it's starving for fuel. So when I stop, I have to keep the gas pedal pushed down just a little bit to keep it from dying. The fuel filter is completely filled and has crystal clear gas in it. It ran like brand new until it's little episode after I swept it out. Turn the key, no hesitation and it would fire and go. Only thing out of the ordinary that I did was put a bottle of Lucas in it. But the problem didn't start for awhile after that. And I drive it a few days a week or at least start it and let it run for a bit. Now the only time it runs smooth is when it's in park or slowly cruising it around 25-40. It even dies sometimes just at idle in park lately. Everything on this motor is brand new. One last thing, when I try to keep it running in park, I mash the gas and it doesn't actually backfire, but it does crack a bit. Just has me stumped. Anyone with anything would be greatly appreciated. Thanks alot guys! Drive safe!