I am in the process of having OER full quarters installed on my '69 350 HO by a reputable shop. He showed me several similar Camaro's and as Terry said, the installation makes a world of difference.
Not sure what area you are in, but I can recommend a guy in the Detroit area that will piece in an OER quarter such that only the most discernable Firebird guy would know it had been done.
The OER and Goodmark quarters are pretty good quality and much cheaper than NOS (if you can find them) and easier to deal with than a donor car because you may open up another can of worms when you start cutting quarters off a 35 year old car.
