Im just trolling through, I searched the build thread and found this one here. I work at national speed and I saw a few comments above wondering why we used a slip joint instead of just a straight pipe on the dump tube.
With the stock wastegate placement, we had to fabricate a extension to put the wastegate in an area where it fit. Slip joints allow small amounts of flex without leaking or breaking. Also preventing vibrations to be passed from the downpipe to the manifold. Making that a straight peice of tubing would be stressful on the manifold since the extension is fairly long and it could promote cracks in the future. I my self have a burns 4-1 slip joint custom collector that does not leak under 27psi of EMAP. (In this case, it might see lower 20s on high boost)
And yes the BC is on the lower portion of the block. Having it mounted on the chassis can create unwanted noises and vibrations. (I had a guy with a subaru that thought his car was knocking/pinging at idle) His BC was mounted on the firewall.
-Taylor