The Vega engine was an all aluminum engine. To save weight GM chose not to sleeve the cylinders, and that was it's downfall. Many did not run 1500 miles before they detonated. It made them real cheap for a young drag racer like myself (and many others). It didn't take much to make them fast. I bought my first Vega for $20 and the previous owner had already removed the engine and transmission for me. 2 weeks later a 300HP 327 and a Powerslide transmission lived in the car.... Slapper bars and M-50s (Tire size back then... About 12 inches wide) on the back and drag tires (skinnies)on the front. That car ran many 13 second quarters before I traded it for a 67 Mustang.