This is our thermostat riser with the -16 AN bung welded to it for a clean one-piece option when running a AN upper radiator hose and the remote lines to the rear of the intake to prevent vapor pockets. The riser is made from 1'' aluminum and has 2 ports taped with 1/4'' NPT thread. Bottom is flat and will use stand gaskets. 
Will fit any small block Chevy. Does not come with hardware, gaskets, fittings or plugs.