39mm Velocity Stack

These are 39mm velocity stacks. I specifically designed them to be a press fit (at .2mm layer height) for a 1974 Honda CB750.

I've also included the .step file in case you need to make any modifications or want to add some sort of screw type thing for a filter screen (recommended)

As a disclaimer:

Velocity stacks greatly increase air inflow for the carburetors. If you are not tuned properly, you could possibly lean your engine out to destruction. These velocity stacks DO NOT have a built in design for a filter screen. Be aware that open stacks can and will allow dirt / anything to get into your intake, which will reduce engine lifespan.

Velocity stacks, especially on CB750 SOHC's, are for experienced tuners. If you are chasing down tuning issues, I'll tell you what anybody on the forums does. Don't do it and just get a damn stock airbox lol.