i got the fans from the local part store the cost was around 150 for both fans and the harness, i also got the wiring harness for the dual fans w/ a/c. the improvements are better gas mileage because the fan is no longer dragging the engine down, it also yields a quicker throttle response, and of course more power... well that's why i plan on doing a regular maintenance check on the fans every couple months or so. I have had on a mustang the aftermarket fans go out but it was from a miswire on the previous owner's part.