Thumbnail Filmstrip of JB-556 BLOCK OFF PLUGS for 5-9/16" Big & Ugly BAU Butterfly Block Off Images
JB-556 Block Off is useful If you are flowing too much air and want to re balance your system down to suit your engine size this is for you .
These work great on Mechanical, but for EFI we recommend retro fitting the Progressive linkage .
When using a 5-9/16" on a lesser engine you can use 1 of these or two for mechanical
injection on engines under 550 cu in or with light blower boost.
Our BAU injector blanks are inserted from behind the butterfly and secure with a bolt and sealer.
5 minute job if the injector is not on the blower
Installs quickly.
For engines not requiring so much air flow, blanking off 1 or 2 butterflies and using a
filter in the operating butterfly, helps throttle control.
You can use as many as you wish.
When the butterflies are closed they are not visible.
Also available in3-11/16", 4-3/8" (BAU3), 5"(BAU2)