1981 Other Ford Models engine haS A LULL AND SLIGHT MISS, AN

OK I HAD A NEW HOLLY 4 BARRAL PUT IN A FEW MONTHS A GO. WHEN I START THIS VAN IT RUNS GREAT, HOW EVER WHEN I PUT IT IN DRIVE AND SIT AT AN IDLE THE ENGINE WILL HAVE A SLIGHT MISS AND IT WILL LULL AND WILL EVEN STALL OUT. I PUT IT IN PARK AND IT SOUNDS GREAT BUT STILL HAS A EVER SO SLIGHT MISS. WHEN I DRIVE IT IT RUNS GREAT, LOTS OF POWER. BUT STOPPING AT LIGHTS I HAVE TO TWO PEDDLE IT.
ALSO IN MY DASH MY BATT LIGHT BLINKS. SOME TIMES IT WONT. BUT MOST OF THE TIME IT BLINKS. WHAT CAN I DO TO FIX THIS PROBLEM. I'M COMING UP FOR NEW TAGS AND NEED THIS TO GO THROUGH. AND WHATS YOUR TAKE ON THE BLINKING BATT LIGHT
THANK YOU FOR YOUR TIME