Since we were prototyping, it wasn't just "hold it up and bolt it up" for us. CAGE had to measure, design, and build while we went along, stretching our install time into the wee hours of the morning on more than one shift. We had already weighed the truck at 3,500 pounds in the front (this is a 6.0L truck). Believe it or not, this is not that much more weight than the front of an outfitted Bronco. Therefore, CAGE knew the static length of the coils when loaded and designed the kit to take Ford Bronco coils for easy, off-the-shelf purchase possibilities for customers.