I recently purchased a long block at a junkyard for 25 dollars not bad. It is a 302 and the heads are in great shape. I want to port them for my next engine build up but would like to know more about the heads. They say DBOE on the underside of the intake opening. They have the openings for smog equip. in the back. Does anyone know what these heads are off of and if they are worth porting?