65 and 66 Mustang seatbelts
 

I would like to know if anyones knows if it is someway to install a shoulder belt on existing waist belts. I would like to make my older cars safer.

Don't have any links or articles for you, but these conversions have been done. Keep looking it will come up. I remember one good web site that detailed the the convsion quite well, but of course I don't remember the address.