I put thundermax on my 06 heritage last season along with the Rineheart pipes and K&N air filter, loved it all last summer. This winter bored it to 95cu in, SE cams and upgraded the tensioners, after that it only took a couple of minutes with the laptop to reprogram the tunner and it is ready to go. One small draw back is the sequence to follow after the battery has been disconnected other than that have had no troubles with it. Do your reshearch, its not cheap