Full-Length Headers
Full-Length Headers will provide the most Torque at low and mid-range rpm and the most Horsepower up top. They curve down and back past the bellhousing and parallel to the ground. This makes it easy to connect to the rest of the exhaust.
The problem with full-length headers is interference. Because of their size, you could run into issues with linkages, the oil filter, dipsticks, accessory brackets, and the starter. Sometimes, ground clearance can also be an issue.
Mid-Length Headers
Mid-Length Headers are shorter than full-length headers. The tubes usually curve back and down at a 45 degree angle to the ground.
The shorter primary tubes will make less low-end torque than a full-length header. But, they are still much better than a stock manifold. The shorter tubes also help with ground clearance.
Some mid-length headers don't exit in the same place on both sides of the engine. Some manufacturers will recommend a special Y-pipe to tie the headers to the exhaust system. Custom bent tubes can also maximize clearance for true dual exhaust.
Shorty Headers
Shorty Headers are almost always application specific. They use short primaries and collectors to fit a header in the space previously occupied by the exhaust manifold.
Shorties provide a significant improvement to exhaust flow over a stock manifold. However, they will not make as much power as full-length headers.
Because of their design, shorties are also easy to install. They usually bolt up to the stock exhaust system.
Block Huggers
Block Huggers are also called "tight-tuck" headers. They are often used on street rods. The primary tubes match the V-angle of the engine block for maximum frame rail clearance.
Block Huggers will provide similar performance to shorty headers. However, they may interfere with the engine mounts and/or crossmember. Custom fabrication is required to use block huggers.
Special Application Headers
For custom applications, Weld-Up Header Kits are available. These kits allow you to build your own headers.
Prefabricated specialty headers are also available. These include headers for:
- Dragsters
- Circle Track
- Truck/Tractor Pull
- Zoomies
- Side Pipes
- Fenderwell Exit
- Etc.