Don, while at the outset the Econo classes looked attractive, in the end they required as much or more money to be competitive as any other class. The cheapest way to campaign the car would be in E.T. Handicap Racing class. There, you could be competitive with a stock 350/'Glide. Success or failure would be determined by the driver's reaction time and consistency of the car.
Heck, you wouldn't even have to compete if you didn't want to. Just show up at the bracket races and make time trial passes.