Exhaust manifold crossover

FWIW, A SB intake gasket kit that has stainless(?) shim block off plates allowing you choice to use or not ...p4286569 (MP '07 cat)
Intake Manifold Gasket Set - 0.060" Thick, w/ Heat Block Off - P4286569

Pretty easy to cut out your own from stainless shim as well if desired.