you could take your stock head and send it to carl bartlett or HPR and if your lucky Q might do it and all three of those guys will tell you to buy a better pipe ... but just fixing the head will do wonders for reliability and performance for your machine ... if you have a 87' have it o-ringed while they have it and ordering a pro-design head will require the same machine work done as the stock head .... they do look cooler and call the machinist prior to purchasing any domes as they all have different opinions on how to set up your motor....good luck and this bike should run with any of the bikes you mentioned if running properly