Notch help...

[JohnnyBoy350]

Hey guys, I want to lower my truck more in the rear and am planning to do an axle flip. I've already removed all but 3 leaves to get it 6 1/2" closer to the earth, the flip should put it another 5" or so? Anyways, looks like a step notch will be required. Might buy a kit or might go the DIY route but I wanted to know if the kits I'm seeing for chevy will fit my GMC since they use different suspension. Any links to some DIY threads would be awesome.

Thanks- John