i have a set of closed chamber large oval port heads . thay where remaned and i never used them . a little rusty from sitting in garage and it will clean up no problems . 200 bucks and 60-70 bucks to ship to you . or trades considered. can get pics if asked. specs from chevy info book: 1966-1976 years cast# is 3917219 on both heads. : chambers are closed : for 366 truck -396-427 truck applications : thay have been referbed and have the blue color : on the valve edges from laping. thats all i know.