Tasca Lightweight 428 Cobra Jet. 1 of 50 Tasca Lightweights. The 1968 Ford Mustang Tasca Lightweight Cobra Jet was the predecessor to the factory Ford Cobra Jet. The first 50 fastbacks were produced at Lightweights. The idea for this car was born from Bob Tasca who was disappointed in Fords performance with the 390ci.