It is true that GM didnt keep good records but from my understanding , if you have a 70 chevelle and a number 1 in the 7th spot of the VIN, then the car was produced in Canada. If so you may be lucky. Canada kept a good record of the cars built and it is possible that they can confirm what kind of car's options it was built with. It would be worth checking out.

After 1968 Chevy did not have a special designation for the SS . It was listed as an option package. You would need the build sheet for the car to see what options the car had. Unfortunatly G.M. did not archive those records very well.