Just had it retuned to take advantage of the inceased airflow. I changed from 4" flex tubing that went from the air filter to the JLT 4-1/2" MAF and went with a 4-1/2" mandrel bent pipe. Amazing, I expected to pick up 20-30 hp, it gained about 70 !!! Went from 680/612 to 751/617... That's thru a 4R100, on pump gas, 9.5:1 CR, 17 lb boost, 16 degrees timing, a nice safe 91 octane tune!