Hot side is made out of 16 gauge mild steel. Has V band's welded on manifold. Has O2 bungs welded in. You have to delete the AC. See my thread in the LS conversion Section For pics of it installed on a car. Hot side is 2 1/2 inch size, T 4 turbo flange. Downpipe is 3 1/2 inch, Wastegate was built for Turbo smart 50 mm waste gate. 200.00 plus shipping SOLD