5.0 cuts out during hot days in 66

My swapped 1994 5.0 in my 66 Mustang convertible cuts out only during really warm days 80 degree plus. It has a Holley electric fuel pump with a Holley low oil pressure shut off. I put a insulator under the 4 barrel carb to see if it was a vapor lock, but it still does it. I noticed that when it starts it get worse when you go around corners or hitting bumps in the road. I does not pop the radiator cap or look like it's overheating. Any ideas welcome,

thanks,

Bill