All i have owned was two cutlasses, and 68, and a 69. I wound up canabilizing the 69 for the 68. When i finally sold the 68 i had added headers (a total bugger to find, took months) an electronic MSD ignition sytem, a massive quadraject carb, and a few other goodies. It still looked stock, she was a real sleeper.
Still miss that car.