Question about Mark VIII IRS install

[fuzzier1]

To all that have installed a Mark VIII IRS in their truck, I see everyone says to level the frame but my question is where are you leveling from? I put a level on the frame right behind the cab and got it level I then drew a line 14 1/2 inches back from the axle centerline (checked from the end of the frame and was real close to the 22 5/16). Went up 1 3/4 fromm the bottom of the frame and then leveled a straight edge from there and the horizontal line is 1 inch from the bottom of the frame. This seems high to me from the pictures I have seen of the rear bracket installation from others project. Does anyone have a close up picture of the rear bracket installation showing how far from the bottom of the frame to the top of the bracket. It would be appreciated. Fuzz

[FrankZX]

The best place to level is behind the core support or that's what I've found.