As I recall they were used from about '73-76 until the Arrows & smaller Challenger became popular. A friend here has one he built awhile back with a big wedge in it running mid 8s when he goes allout. I'd love to have one but the wheelbase on them needs to be lengthened & from what I'm told they're kind of a handful to drive. Historically they weren't all that successful either as ProStockers or as Comp Elim. cars which they usually ran in once NHRA started screwing with the P/S guys who ran them.......