Seatbelt Solutions 3 point conversion

Just bought a set of 3 point conversion belts for my '74 Duster from Seatbelt Solutions. They use the stock bolt locations for install. My originals had duel retractors where these have a single retractor. The company told me they would give a more modern clean look. My complaint is that they don't retract enough. There is a lot of slack left in the belt that looks pretty slopppy. Anyone used these belts in their build? I was thinking of having my originals rebuilt, but I thought this might be less bulky and would eliminate the belt having to retract into the rear seat panel. Also half the price of a re-build.