On my 67 Dodge R/T I had a STR-14 intake 2 650 DP Holley carbs.(race-car no air filters) Put a Hemi scoop on it & did not seal it,and it slowed it down bad.I run it with the hood off to see what the problem was,the air blowing across the top of carbs would start pulling gas out the vent tubes. Put a tray on it to seal the carbs picked up.06 in the 1/8 mile.