The stock flex pipe is welded to the stock manifold. So unless you wanna cut it off and try to make it work then I suggest just buying their flex pipe. I know it's expensive but it's worth it. I think it will save you some headaches later on when you go to install it.
Just to clarify the 08+ the manifold is NOT welded to the mani cat
cossie im, cfm 67mm tb, 3" dp, 3" exhaust and custom turbo kit, holset hx35 turbo on 13psi, exedy stage 2 clutch and flywheel
Stock long block 353whp 280lbtq, 13psi
team duratec #94
D23 crew #9.