These high quality machined aluminum velocity stacks are designed specifically to fit SU H6 / HS6 and 1.75 inch Zenith-Stromberg carburetors on many Triumph and MG engines. They'll also fit the Hitachi clone of the SU (HS6 and H6), which are found on some Datsun engines.
Dyno tests have shown an amazing increase of 4-6 horsepower on four cylinder Triumph engines, and up to an 8 horsepower increase on the Triumph GT-6. The overall height including mounting flange is 2.8", and the bell has a maximum OD of 5.1". Sold individually.
For a low-profile filter, we offer a Custom Velocity Stack Filter, Part No. 3894-127 (sold separately) that slips over the end of the air horn and adds less than 1/2" to the air horn length!