* The specific Judson supercharger model: Judson made various superchargers with different displacement and efficiency characteristics. A larger, more efficient supercharger will add more horsepower than a smaller, less efficient one.
* Engine condition and tuning: A well-maintained, properly tuned engine will respond better to forced induction than a neglected one.
* Intake and exhaust systems: Restrictive intake and exhaust systems will limit the potential horsepower gains. The supercharger needs to be able to breathe efficiently.
* Fuel delivery system: The fuel system must be able to supply enough fuel to support the increased air intake; otherwise, the engine will be fuel starved, limiting power gains. This often requires carburetion modifications or a fuel injection system upgrade.
Without knowing the specific Judson supercharger model and the engine's condition and supporting systems, it's impossible to give a precise horsepower increase figure. You might see anywhere from a modest increase (perhaps 10-15hp) to a significant boost (possibly doubling or even tripling the horsepower, although this would likely require substantial supporting modifications). You'd need to consult documentation specific to the particular Judson supercharger and engine combination, or perform extensive testing to determine the actual horsepower gain.
