The only version of that kit I've ever seen is the "Color Me Gone" car.. that came with a dual-quad hemi. Ended up putting the engine, tranny, floorpan and suspension from that kit into a Johan '68 Fury copcar.
Love that Duster- nice detail. Where did you get the scale slant? I've got a Duster kit that came w/ a Viper V10, but I swapped that into a '58 Plymouth kit, so the Duster needs an engine.