I've owned a 1980 and a 1981 Datsun 280zx which my 81 was a parts car, I was looking up recalls on cars I had and discovered the 1979-1980 seat belts had a recall of the seat belts letting go in major even to moderate accidents. Never happened to me, I've lost track of the coding and the website where I got it at but wanted to let you know that your car might be your baby, but also maybe a deathtrap. The problem was fixed for the 1982 and 83 for sure, I think the 1981 may have had the same series of seatbelt, if so, I picked one up in a junkyard that would fit the car. The seat belts would appear to hold when you yank fast on them, but in the event of an accident, would have little holding force and freespool out during a collision.