The Swingers(basic) came with all size motors(6 cyl - small blocks). The 340 Swinger were was a class of its own, without all the bells and whistles. The GT's were sporty, without the Hi-Po motors and the GTS's were the sporty, with the Hi-Po engines(340, 383 or 440). The 68' 426 Hemi's were a class of their own.