[cnhorn63]

This is a great forum, this is the first time that I have posted a thread. I have a 1978 TA with a '72 455 with #66 heads, crower cam, 280 duration 465 lift, hooker headers, holley street dominator, holley 750 vac sec, holley mechanical fuel pump. I am experiencing a severe stumble and miss when the vehicle is under load accelerating from a stop. I recently replaced the HEI since the original HEI that came with the car failed big time. The coil had burned a small hole through the center of the cap and rotor. I think the ttiny bushing and spring that sits beneath the coil failed, it was broken in two and charred. I replaced the HEI with a new unit from Larry Rowe. Set the timing at 12 degrees. The vehicle idled perfect and ran excellent for the first 3 miles, very crisp throttle response. Stopped at a light accelerated normally and the same problem ocurred, sever stumble and miss, vehicle would barely get above 30 mph. Pulled the distributor cap and everything inside is fine, no damage or burn through etc. The engine will idle fine, but will begin to miss at 2500 rpms and higher while in park. Under load it will miss from idle on up. Not sure where to begin, ignition problem or fuel problem.