'76 400 in a '73 duster

I put a 400 of the same sort in a D150 truck. Only thing I did was remove the 2bbl and put a 4bbl on it with a set of used headers. Long block was stock and never apart. Truck was a auto with 3.21 gears. It ran a 14.50

I'm sure in a Duster with 4.11's, you'll be way below my E.T.