Exhaust Manifold I.D.?

Looked at a Duster this weekend which had a 383 in it. It had manifolds on it and i investigated to check the fit and it all looked good so i thought i'd get the numbers and post em here and see what you fellers think they are off of. Passenger side was 28006900 and the drivers side was 2512050-2. Very hard to read so the numbers may be off so anything close might be worth posting. Thanks guys. The car is for sale and might be a good deal.