Bill Smith
Founder, 1929-2014
Speedy Bill
Since 1952
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America's Oldest Speed Shop ®


17.5 Volt Step-Up Box

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17.5 Volt Step-Up Box
17.5 Volt Step-Up Box
17.5 Volt Step-Up Box
17.5 Volt Step-Up Box

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Please NOTE the following about this product:

  • This product is discontinued.



Q & A

What's in the Box

If you aren't running the "little black box," you're leaving horsepower on the table. Our little black box is an alternative to running a 16-18 volt battery. The box simply increases and maintains the voltage at 17.5-17.7 volts and supplies the correct amperage at the correct rpm to give you maximum power. 

The box easily connects between your ignition switch and the battery feed wire on your HEI or MSD box. Works with MSD, Accel and other ignition systems. If not built to handle 18 volts, circuitry is protected from damage with the simple, effective and elegant use of an inline fuse.

935-64000 Instructions (PDF)


  • 4-1/8" x 2-3/8" x 2"
  • Orange Wire: 12 volt input with 15 amp fuse
  • Black Wire: ground
  • Yellow Wire: voltage output to ignition, MSD or HEI, ect.