I attached the SRBs to my latest project (still un-named) and rigged up a harness to allow the top section to come down parallel to the ground. As you'll see below, it is not perfectly parallel. I decided just a skosh of up-angle would be good. I still have to attach the shock cords to the upper and lower Kevlar leaders. The current CG is about at 26", which gives an unloaded margin of ~3.7 and ~1.8 with a D12. The 'chutes will reside around that point so I doubt they will affect the margin much. I still have to put in some 'chutes, weigh it and do a final assessment of stability, speed off the rod, etc. My gut says it is heavier than planned, which may mean reloads will be required.