About how much more horsepower can i expect to gain on a stock 1966 Mustang 2bbl 289 engine after I upgrade the following parts? edelbrock 4bbl performer intake and edelbrock carb. Upgrade the air intake to a k&n air filter. Add tornado fuel saver. upgade from stock 2 1/4 dual exhaust to a 2 1/2 flowmaster 40 series dual exhaust with H pipe and shorty headers. how much more horsepower can I expect with all of the followiing upgrades?