Automatic must be a C4. Will not fit top loader transmission, may need to modify clutch linkage.

Ultra duty 14 guage primary tube: heavy guage primary tubes prevent burn-through caused by the excessive exhaust temperatures created by performance engines, or while under heavy hauling or towing conditions.
Thermal coating: Hedman's Ceramic-Metallic coating protects your hedder against the elements, and withstands temperatures up to 1400 degree F. The thermal coating keeps heat inside the primary tubes for lower engine compartment temperatures and faster exhaust flow.
3/8 flanges: Prevents warping to ensure leak free seal,
Installing coated headers during break in period will cause the header to discolor.