SKU: JB-438
JOE BLO Block off Plugs - BLACK 4-3/8"- Big and Ugly BAU Butterfly Block

Big and Ugly  Block off Plug. 

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 .

Our BAU injector blanks are inserted from behind the butterfly and secure with a bolt and sealer. 5 minute job if it is off 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 in 3-11/16", 5" and 5-9/16" (BAU2 and BAU1)

https://www.permatex.com/products/gasketing/gasket-sealants/permatex-permashield-fuel-resistant-gasket-dressing-flange-sealant/