I did a conversion of a 4.3 Chevy engine to a 48 Willys Jeep going from a computer-controlled throttle body injection system to a Rochester 2-barrel carburetor and a HEI 4.3 Chevy distributor that was made prior to computer controlled engines. The engine starts and runs idle very smoothly but will not accelerate. The engine under acceleration fires out the exhaust system and will not rev on up. My jeep is fully restored and ready to go except for this problem. Does anyone have any suggestions I can do to remedy this problem?