Suburban Year by Year Question

[eyebuzz]

Hi All,

I used to be on the 67-72 Suburban forum - but getting the itch to jump back in - at least to the Suburban world. It will be awhile as I've got to save up the cash....but I love the 73-91 body style. I've got some year by year questions - please feel free if you can only fill in one detail that will help.

From what I've seen on Wikipedia: '81 is the first year for the 700R4 trans; '82 diesels were introduced; '85 new grill; '86-'87 fuel injection added; '90 ABS (for rear) added; '91 4L80-E trans --- but this leaves a lot of holes and I couldn't find a year by year model changes/update list...So:

1) What year were 3 point seat belts offered? (ever available for rear seats?)

2) (Dark) Window tinting - what year did this become "standard" (I personally don't like it).

3) What year were head restraints/rests available? (ever available for rear seats?)

4) What year did power windows come in? Were they an option and roll down ones still available ('til what year)?

5) What was more popular - barn doors or clam shell?

6) Are all the transmissions before '81 3 speed? Was the 3 speed still an option after '81?

7) What differential gearing was standard on 1/2 ton models? What was available? (sorry if this is way too general a question).

8) When did 6 digit odometers come in? (not counting the 1/10th)

Thanks All!