When you go to car shows full of Detroit machinery, you'll probably see more of the Buick GS than you will of the regular Skylark, much as you do with the GTO-versus-LeMans situation. Here's a Skylark owner who took the best-looking feature of the GS (the hood) and kept the rest of the Skylark badging and trim, which I think works pretty well. This car isn't perfect by any means- in fact, it's a little battered- but it's in excellent shape for what it is: a nearly 40-year-old car that parks in a busy downtown urban area and sees regular street service.
The standard '69 Skylark engine was a 230 horsepower, 10 billion foot-pounds torque (slight exaggeration) 350-cubic-inch V8. If you got the GS 350, your engine was a higher-compression 350 with280 horsepower; GS 400 buyers got the monster 340-horse 400 engine. There's no telling what's in this car; by this time it might have a junkyard 455 or even a Pontiac or Olds powerplant.