It'll be a mildly noticeable difference in heat under there. Don't do it thinking you'll gain any real power.
It helps non-forced inducted engines by keeping more heat in the exhaust which leads to faster exhaust velocity. Again, not a "big" difference. It's mostly noticeable in high-effort builds (i.e.- 500hp+ naturally aspirated small blocks may gain another 10hp or so with coated vs non-coated headers).
Where ceramic coating (outside and inside) really helps is in turbocharged vehicles since their pre-turbine exhaust temps are much higher... not only from the heat of combustion (1300+ EGTs), but also drive pressure. Generally speaking a turbo ideal for 20psi of boost on a stock-ish 5.3 can have 20-40psi drive pressure, which adds considerable heat and makes the headers glow red hot. The coating lets you perform at high boost for longer periods, lessening the chance of a blow-out.
If the extra cost isn't a concern to you, then go for it. If anything, it'll lengthen the life of the headers and gaskets by buffering thermal shock.
It helps non-forced inducted engines by keeping more heat in the exhaust which leads to faster exhaust velocity. Again, not a "big" difference. It's mostly noticeable in high-effort builds (i.e.- 500hp+ naturally aspirated small blocks may gain another 10hp or so with coated vs non-coated headers).
Where ceramic coating (outside and inside) really helps is in turbocharged vehicles since their pre-turbine exhaust temps are much higher... not only from the heat of combustion (1300+ EGTs), but also drive pressure. Generally speaking a turbo ideal for 20psi of boost on a stock-ish 5.3 can have 20-40psi drive pressure, which adds considerable heat and makes the headers glow red hot. The coating lets you perform at high boost for longer periods, lessening the chance of a blow-out.
If the extra cost isn't a concern to you, then go for it. If anything, it'll lengthen the life of the headers and gaskets by buffering thermal shock.
