I have a set of these exact heads. 049 castings are probably the best OEM oval heads that chevrolet made. They flow very well after some clean up porting as well as the installation of bigger (IN. 2.19/EX 1.88) valves. There an open chamber head as well. The combustion chamber volume varies on these heads anywhere from 114 to 119 cc's. The only way to find out what you have is to cc the heads or at least one chamber on each head. Mine came out to 120 cc's but the chambers were polished and also unshouded for the bigger valves that were installed. Hope this helps...