weird cutting out problem

My completely stock '74 has done this a couple times since the heat is here. Take off after idling a minute or so and about halfway through 2nd gear it lays over for a couple seconds, like I let off the gas. Then it picks back up and runs fine.

The fuel system is new all the way including the carb, same with the ign. I still have the metal carb line and it looks like the factory 192 or so t-stat so I'll do some work to cool it down and see if it helps.