i have a 93 camaro 3.4L with a flowmaster 40's series with dual outlets. its too loud for my state and i was wondering what size the pipe from the cat to muffler is? i want to install a flowmaster Hushpower II between the cat and the 40 series to quiet it down a little.

thanks a bunch.

 

I take it you don't have a set of large calipers?
Take a wire coat hanger, cut it, bend it into a hoop, and get it until the two ends just slip over the pipe without spreading apart. Then take a measure between the two ends.