I've been wanting to replace the stock mufflers on my 81 SH for some time. Bought the commando pipes and 1.5" headers since they were on sale at Yamahaxs650.com. I can't believe how much these pipes woke up my 650. Just pulls so much better across the revs. If anyone is running the overly restrictive stock pipes on your Specials, you will not be dissappointed with these pipes. Just make sure your carb is jetted to handle the free flowing exhaust, and to prevent blueing. The exhaust note is so much better as well. Wish I would have done this upgrade much sooner. No, I'm not being paid to say this.