hey dude, got those prices, well of course you'll need a new head gasket, so we'll $50-$150, depending if you get an o.k. one, or if u get a high tech one filled with 30 types of metal. round $30 for valve stem seals. and money for labor, but i dunno how much...it might be a simple job that you can do or simple enough that they wont charge u an ass load for labor, or they might charge you a bunch for labor because they're doing "headwork". i really dont know, call a good shop and have them give you an estimate. just tell them that you need new vlalve stem seals put in, dont say anything about the smokie exhaust, cuz then they'll want to tear your motor apart (hopefully not). does anybody have experience changing these out?