How much of rubbing alcohol should I put inside the gas tank to pass the hydrocarbon levels for emission testing on 1995 Chevy Suburban 5.7 liter?

Adding rubbing alcohol to your gas tank is not a recommended or effective method for passing emission tests. It could potentially damage your engine or fuel system and may be illegal. Instead, consider having your vehicle properly serviced, including a tune-up, replacing the fuel filter, or using a fuel additive designed for emissions reduction. It's best to address the underlying issues causing high hydrocarbon levels rather than attempting a quick fix.