Very nice! Rare truck too. Last yr for Jimmy and there was only 3500 or so built.
As for a tach, no after '82 on option sheet but there are a few people who did get them installed from factory as far as '85 if I recall correctly.
That being said, you have the electric speedo (90-91) so it complicates factory tach install but it can be done. Some cutting and Dremel work is involved due to speedo taking up a lot of room in the housing.
I put one in my '89 Blazer but I have last yr for cable driven speedo.
