Whiskey, I have two of the Jett .40's that have been raced in both 424, and 426 Quickie. In the 424 configurations my engines seem to be on a par with the TT and Evolutions. In the 426 configuration my engines are NOT on a par with the "fast guys". For our 424 event the Jett was approved with a venturi, while the TT and Evo have carburetors. I don't know what your rules require, but if carburetors are required, that will increase the price of the Jett. Sparky, and I are not trying to steer you away from the Jett. We just think you could get the same performance from the Thunder Tiger. Our Sport Quickie 500 rules limited the engines to .40 displacement. That rule was waved for the Evolution because the performance of the .46 was closer to the Thunder Tiger .40. We also discovered that the Evolutions don't seem to have the same quality, and durability as the TT's. I have two of the Evolutions, which ran fairly well for a short while, before they started loosing power.