[Mgs] fuel pump?

[1971-red-mgb]

Talking about fuel pumps, (where we?) anyway I filled up on gas tonight,  got
on the interstate and suddenly lost power, no matter how much I depressed the
gas pedal I was barely able to maintain speed,  after a few minutes I suddenly
I got full power back and the engine pulled strong, I then drove  60 or more
miles with out any incident, I'm betting some obstruction got in the fuel
line, or the fuel pump is going slowly, any thoughts?