I am happy with the Thompson Performance Powerblast Plate. I just installed one in my '72 C20 with an Edelbrock Performer carburetor and there was an instant improvement in throttle response. Before installation there was a half second lag when you stomped on the gas pedal, and now it revs instantly and does burnouts easily. This is in a low horsepower crate 350.
As others have stated above, there is no difference in mileage or overall power as it only affects the accelerator jets.
