What did the GS option add to a base skylark. I ask because I have seen some GS cars that were stripper models with no options then have seen others with a lot of options.
Mostly a performance package: V8, 4-barrel carb, dual exhaust, ram air system, sport wheels, rear suspension upgrades. Probably some other stuff, but that is all I can recall without digging.
I'll answer for the first ones in 1965: 401 engine heavy duty transmission, floor shift boxed frame heavy duty rear axle bearings crossflow radiator dual exhaust heavy duty springs, shocks, front stabilizer bar wider wheels and tires bucket seats specific ornamentation
Lower rear gear ratio (my list is 70-72). You could get all sorts of combinations of various options (interior, exterior, etc.) in in these years.
