Need 1973 Duster Front Bumper Measurement

Locomotion said
No. As mentioned, '73 and a lot of '74's had regular bumper brackets. Late '74 model run started using the "5mph" bumpers which stuck out more and used shock absorber style brackets in the front. All '74's on up had the shock absorber style brackets on the rear.

The later bumpers also have massive & heavy bracing inside. Bolt pattern of the carriage bolts on the surface is different so the bumpers don't interchange. I believe the later ones have an extra pair of carriage bolts near the top on either side of the front license plate area.

Nope. Shock mounted front bumpers started in ‘74, but then in December they went back to standard mount bumpers because of some kind of production or supply issue. My ‘74 Duster, built in June of ‘74, had a standard mount front bumper. It also has all three mounting holes on the frame rails, so you can bolt standard brackets or shock mounts to it. Which is why I was able to put a ‘71 front clip on it without adding any frame mounts.