I'm sure it adds HP over the original 2" to 1 7/8" factory exhaust, which was in really miserable shape. It's not more efficient than open headers or straight pipes but is much nicer for top down cruising without going deaf.
An X pipe is more efficient than an H pipe, which is more efficient than a crossflow muffler, but since you CANNOT fit a X or H pipe above a convertible's X brace the crossflow was a nice compromise.
The tail pipes exit under the quarters as original, not out the back.
Vikki 1969 Goldenrod Yellow / black 400 convertible numbers matching
