As far as I have been told the 68 Darts that got 440's were installed at Mr Norms Grand Spaulding Dodge. The 69 factory 440's were installed at Hurst but then sent back to the factory and could be ordered at any Dodge dealer. No 440 Darts in 68 came from the factory as far as I know Mr Norm's did the only 68 440 Darts and he changed the GTS to GSS for Grand Spaulding Special as thats what I think it stood for. Ron