I know a guy who has a 1981 Z28. Its a 383/powerglide with a tall rear. His Camaro runs 12.80s all day long. He tested the Flowmaster American Thunder and the Dynomax Mufflers on the track... ready for this... his Camaro ran 2 tenths of second faster with the Dynomax units.
Don't make the same mistake I did... buy Dynomax
