Blocking the crossover didn't really effect performance but did change the note a little. It made it so each side has it's own note, kind of separated the sound so you hear each cyl. individually instead of a blended sound. I didn't notice a change one way or the other on either of our bikes seat of the pants. Now if I did a before and after dyno there may have been some small difference but I really don't know that for sure since I didn't do a before or after.

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