Yup, what Charlie said! AFR has some very affordable heads that perform excellent, along with the Edelbrock RPM's and Victor Jr's. for a bit more performance. Trick flow also has a very nice set (Track Heat) that will flow plenty for a 383 Chevy.... By the time you pay the labor on new seats, guides, then the parts bill for new valves, springs, and retainers and miscellaneous you'll be over the price of new one's and still not have the performance.. Some of the new head designs perform better out of the box then a reworked, flowed, and cc'd set of old design heads.....