Design Engineering 50519 Form-A-Shield 12″ x 21″ Extreme Heat Protection up to 1400°F (1.75 sq ft)

I now prefer this to basically any other method of blocking heat from manifolds, but as a forewarning you will need metal shears/snips, stainless steel (high heat) cable ties, and to ensure you use the provided gloves (and a mask/respirator) as the packing is fiberglass.The packing will smoke/smell for approximately two hours or equivalent to about 100 miles or so. Afterwards, you may still get a little smoke/smell, but it will not be visible and prevent you from using outside HVAC intake like initially. It is excellent at blocking heat on turbo manifolds, and I recently applied it to an NA header I plan to use at some point in the future.