From my experience: 1) If it hasn't already been done, do yourself a favor and modify it so you can bolt the plenum to the runners from inside the plenum. It makes life much easier. You will need to run stat-o-seals or something similiar. 2) 1206's are hard to fit with most of the TPI manifolds. Be careful when you seal then up to the heads for the last time - it's easy to get leaks with 1206's. Right Stuff or good RTV are a help.

Good luck