This is going in my 66 el camino with a 2004r and 308 posi rear gears. As far as the opti I have a new one and changing it on mine is really simple. I didn't even think about the valve covers. I was under the impression that the 1.6 rockers would fit. I will double check that before I install. I already have the 350 LT1 installed and have been driving on a daily basis for over a year. I have 26# injectors on the 350 and it's good to know I only have to go to 30#. The AFR heads have provisions for both the early style and late style valve covers so I think I will be going with the early style just to trick some people up as far as what I have under the hood.The fender emblems still read 327.