I also have an 08 tahoe ltz with power boards, I have purchased husky molded mud guards. To put them on was not fun, but it can be done. You have to cut the black cover on the front end of the board and also the one in the back of the board, there are screws holding these covers on. It is molded as one piece. After you cut them you can slide them on to make the board shorter and re install the screws. You then have to loosen up the adjustment screws on the board to more it from front to back. now is a good time to install the mud guard that way you know how much room you need to move the board to the back of the truck. After you have adjusted them to make room for the mud guards, you can then tighten up the screws to adjust the board and repeat on the other side. If you have access to a lift I would highly recommend it in makes the job much easier. But just remember to put the truck back on the ground to check your clearences on the running board to the rear tire. Hope this helps MIke