I don't know anything about those pipes, but I do know there were very few twin pipe sets that put out more than the stock single pipe. Most brands lost horsepower. One more thing, you may have to raise your needles as the stock pipe pulls more fuel in the midrange than your twins will. I don't want to see you burn her down.
i thought bout putting stock pipe back on it i did rejet it stock it was 300 on clut and 270 recoil i put a 310 and 300 it has awesome top end power but lacks low and mid..