Howdy AquaTune, I installed this AquaThrust unit on my '68 Chevelle with the 327 engine and I'm running at least 40 more horsepower ( hard to tell), my engine sounds a little quieter, and I'm glad of that, because it was border line illegal with the higher lift cam over 3000 rpm. I picked up 1000 RPM more of a hard pull (5800 to 6800, had to shift, didn't want to break anything). Before, the engine's pull would drop off after 5800 rpm. What I could check for regarding HP was I dropped my, from a roll, 10 to 60 mph from around a little over 4 seconds as opposed from, a dead stop, 0 to 65 in around 3 seconds or a hair over, impressive, everything was happening so fast, even with 3.73 gears. I went from 1st, 2nd at 6800 to 7000 rpm's, to 6th and ZIP, I'm on the freeway. That got the old heart pumping. That's enough horsepower for me, I wanted mileage and looks like I got both. I'm going to check that with a stop watch one time to see exactly what it is, but that is a very close estimate. Gas mileage I don't know yet. I'll check it later, but I'm sure it's better. You can stand behind the car and not smell exhaust as bad as before. In fact, you can't smell much at all. Simple to install. Oh, you are supposed to run medium grade gas, not Premium. It will run better because it burns faster and more complete, also you increase the distributor advance 7 degrees more so you get a longer burn. You believe that....wow. The engine runs cooler and the engine oil is suppose to run 25 degrees cooler, which I believe. It runs on a Qt bottle of distilled water and 70% alcohol in a 50% - 50% mix. That good for 1 tank full. Should pay for itself with gas mileage increase. Thanks for reminding me about this system Jerry, you gave that push and I'm glad I did it. I thought all you Hot Rodders out there may want to know about an increase of horse power at a reasonable per dollar spent. You're also helping the environment out at the same time for your children. Thanks, I achieved everything you folks promised and a whole lot more.