Can someone please tell me what chevy "turbo" heads are? Me and a friend are building a motor for his 89 rs and was wondering what these are and how much horsepower are they worth with a good port and polish job? These i believe are 2.02/1.60 heads.

 

Yeah they are the 492 heads right? They have the ability to flow tons on the top end and can make great power. They came on the 68-71 Z28's.