i have a 73 2L that was recently rebuilt and i almost let it run out of gas last week and it hasent been happy since. i've run a tank and a half through it since and i have been adding a fuel cleaner to try and fix the problem.
what happens is the engine starts to decelerate on it's own asif it isent getting fuel. if i put my foot down it sometimes recovers but i usually have to pull off the road. and oddly it only happens randomly and usually starts up after a couple trys.