its all about the manifold...... the manifold will almost matter more then the tuned pipe.......... the mellowest manifold is a 41021, especially on the extra long stroke engines....doesn't mater if its a 9886 or a 9901 as long as its on a 41021 the power will be toned down......... Swap over to a 41001 and the 9901 will become a monster and 9886 will be even moreso a monster........ My advice for a Legend 7 is a 9886/41001, 9901/41001, 9853/41001......you could also check out the 41032 manifold...... avoid the 41021 as the extra long stroke don't like it overly much, loses about 15 % power as opposed to the 41001