talking about red headers the first predator carb. i ran i didn't know they want made for the st.(at the time they didn't have a st. carb.) so i bolted it on a 350 4-71 blown motor and took off up the st. run good, so i came on back to the shop and raised the hood and like to have fell out. the headers was so hot they was yellow, im talking top to bottom, you could see through them, I knew I had cooked the motor, so I called predator and they told me there was no idle circuit and would run lean if you drove it on the St. didn't hurt the motor though.