lot of negative talk here but for sure, the older cars unlike the new designs do not have crumple zones built it to sacrifice the frame and outer structure of the car to save the occupant. However that being said, if you are installing belts common sense applies....if at all possible, do incorporate 3 point belts and make good use of the shoulder strap. These are not that hard to install in the older car if you buy the right model belts....I have no aftermarket brand that I would recommend here. I also do not care for the most commonly referred to brand cheap washers. I also suggest you take a good in depth assessment of your older cars metal before any install. I use donor set ups for my cars and have never had to crash test them, but I feel more than comfortable they will do the task if called upon. At least at one time the design was tested. You have never seen the NHTSB issue a statement saying at x year change a belt. Some calls are made after an accident however and a rebuild of the car. IF you do go to the donor belts, just be careful the vehicle you glean them from were never exposed to the elements while in-op with broken glass or missing doors allowing the elements in, again, common sense.