My engine has 9.5-1 compression. Can I run a blower and still use pump gas?

We do not recommend it. The higher the static compression ratio of the engine the less boost you can run and still use 93-94 octane pump fuel. Usually on a 9.5-1 engine the most boost you can run is about 2 psi before you get above the octane rating of pump gas. That level of boost will usually not make enough additional horsepower increase to offset the cost of the blower kit. Remember, it takes horsepower to make horsepower with a roots type blower. The car will run slower if you do not make enough horsepower to run the blower!