HELP ON A SMALL BLOCK CHEVY?

Question

i have a 1978 el camino with a 305 which is just temperary but i have hooker long tube headers,edelbrock intake manifold "0-5500rpm" and a edelbrock carb. and some msd components.fist when i would race even thought the speedometer says 85 it still goes at the same speed but after i put the manifold as soon as it hit 85-90 its almost like a kick back like if it resuses to go so my question is what is it that causes that to happen

Answer 1

Could the flaps be closing up ,when there should be opening ,I,m talking about the manifold  flaps . When you have the engine running the flaps should be rocking and when you give it gas there should open up to let the exhaust out .