Dont'T know if this is gonna help you, but try to picture it, 1st does your truck fit in the garage now, if it does there will be know problem, here it goes----- if you measure from the ground up to the fender flare, you will get a measurement of 40", if and when you get the pirch mod done ,you will get a measurment of 41 3/4", so if the back part of you roof clear's the garage, your only lifting the front 1 3/4 of an inch higher in the front, making it level.
2nd There are impack safty rules that have to be followed buy the manufacturer, front impack , they want the 2 vehicles to take the brunt of the crash, reducing the energy the person or persons involved will get, and lessen the injuries, raised vehicle will hit higher on the other, possably dirving over and or crushing the other, or other vehicle going under possably flipping other vehicle. But there are companies that make lift kits that are legal, and there's no problems, look at the people who lift there trucks so high, go through DOT TILT TEST, and pass, drive on the streets. Its all about what the manufacturer has to follow.
3rd If it don't fit in the garage, so what do it, you'll love it, drove my truck stock for a year, questioned many on the forum, and all I can say is LOVE IT, like stated by others, LESS NOSE DIVE, TURNS WITH OUT THAT MUSSY BOATIE FEEL, SUSPENSION REACTS FASTER IF YOU OFF ROAD, AND JUMP THE TRUCK, BETTER CHANCE OF KEEPING THE NOSE OUT OF THE DIRT, (lawn darting your truck)GIVES YOU THAT ADDED CLEARENC,AND LOOKS WAY WAY BETTER.