Header Adapter Plates, Flange Spacers & Kits

Header and cylinder head adapter plates allow you to bolt big tube headers with a different bolt pattern onto cylinder heads using a standard bolt pattern. This results in the ability for the engine to produce more horsepower from the improved breathing.

Header adapter plates and spacers move the headers outward, which can help to clear chassis, suspension, and other components that may be in the way of routing the exhaust headers. Thickness typically ranges from 3/8" to 5/8", which can sometimes be just enough for that perfect fit.

When using race headers that have tube diameters typically larger than 1 3/4", the header flange bolt holes will not be able to line up with the cylinder head without relocating them as the tubes will partially cover the original header bolt holes. A header adapter flange kit contains a plate that has been drilled and designed to bolt to the cylinder heads with a countersunk plate bolt or screw design (to allow the headers to bolt to the flanges flush) and with threaded holes for headers to bolt to the adapters. The exhaust holes are designed to be modified for proper port-matching between the header exhaust manifold adapter plate and cylinder head exhaust ports. A header gasket is required between the adapter and cylinder head as well as the adapter and headers.

Exhaust header spacers are metal flanges that are designed to go between the cylinder head and headers, pushing the headers out. A header spacer is often used when the headers are hitting obstacles and by being moved out from the engine, will allow proper clearance required for installation.