Modern Seat Belts?

Yes...but! The two things I suggest you consider are these:

1. Reel location. If you go with a single bolt set up like I did with the 73, the vertical run of the upper belt goes through the rear door opening. The belt has to be pulled aside to allow a passenger to enter. The reel also intrudes into rear foot room. I didn't see it as a deal breaker.
2. The webbing for the buckle needs to be long enough to pass through a bench seat and have reasonable access to the buckle. The van set that I used on the 73 is so short that anyone wanting to move the seat forward, from my position (I'm 5'11") will not be able to reach the release button after buckling in. I don't drive with the seat all the way back, but it's close. FWIW, I'm looking for another set with longer buckle end webbing. Longer buckle webbing will let the upper belt run lower across your chest.