had some on my big blocks they work great i used one with long runners and a mid plenum .yes you need to know how to tune it in and use the rigth cfm on the carbs . i had a in line autolite1200 cfm ?? ford carb on it had to make a top plate for the carb it was cool but i kept the hand made air cleaner with a mopar air filter on at all times the carb had Ford on the top of the carb