Swap A833 for Auto - 71 Duster 340

I would estimate your car is putting out 200-225 hp. Try a tuning forum and get back to us. Did I hear somebody say compression test? Yes...probably dished pistons around 8 to 1. A 340 with a 750 and a 3.23 could be a low compression stock worn out dog and still turn those 2.75x60 tires.