I've done two conversions. One of the Demon and one on the Dart. I used serviceable Mopar belts from salvage yards.
If the car had taken a hit to the front end, I did not consider getting the belts due to potential fatigue issues. If belt was cut or frayed, I did not consider it usable. Likewise, I considered any belt that had mud or dirt ground into it to be unusuable.
I checked the reel to make sure it extended and retracted the belt smoothly as installed in the donor vehicle. I also inspected the reel to insure it turned freely when the latch was held back and that it rolled true on the axle.
When I installed them in my cars, I made sure that the inertia reel was oriented the same way it was in the donor car. In both cases, the axle of the reel was parallel to the ground. I had to modify the fixed end of the outboard belt so that it would fit on the same bolt as the reel. The donor vehicles had different bolts for the reel and the fixed end of the belt.
They lock perfectly.
The set in the Dart came out of a van. I sometimes have trouble getting the reel to take up the belt when I unfasten it. Sometimes I have trouble getting it to take a set. The solution is the same. Reach behind the seat and give a tug to the belt as it enters the reel cover. That corrects the problem 90% of the time. The remaining 10%, the belt is usually twisted and does not pass through the upper mount properly. Once the belt is correctly set, I can lean forward to work the wipers, A/C, or radio with the belt extending and retracting properly. If I lean forward quickly, it locks up.
The reasons I converted in the first place were, I wanted a single belt latch system, and I needed to lower the hinge point for my upper body restraint. Previously, the shoulder belt in either car would cut into my neck because I sit so far to the rear of the car. The upper anchor is tethered in a way that lowers the point where the belt crosses my body. Instead of crossing me at the neck, it now crosses me right at the collar bone. It is much more comfortable.
Drawbacks:
- The reel occupies a bit of real estate in the rear footwell.
- When getting into the Dart, it is necessary to evade the belt rising from the floor as well as the upper restraint tether when entering the rear seat. On the Demon, I place my arm behind the belts when I tip the seatback for entrance and exit to the rear seat.
- On both cars there is no easy way to get the belts out of the way for easy access to the rear seat.
- The webbing on the buckle end of van seatbelts is very short. If the seat is forward of the midpoint of seat travel, the buckle will not be accessible. (In order to lengthen the buckle end of the belt, and to change colors, I will replace with a car belt system.) I guess I could say that while belts from the front seats on a van will work, I do not recommend them.
