I would be pissed! Get a stock motor for cheap and add 100 shot and you'll have more Hp.
If it makes you feel better, my MP 380 hp in a 3480 lb duster doesnt go faster than 14s. $800 stall, tti headers and lower gears added. Did NO better than the stock reman 360, stock convertor and non posi gears. I WASTED all that money for nothing and only get 9 miles per gallon. What a piece of garbage!