I *think* your '81 will be ok. If your steering column has the bolt going through it to retain the steering shaft to the column, then I believe it's a "bolt in".
The people that have problems as I recall are those with the older columns that use a pinch bolt, instead of the through bolt.
Someone just installed one of these, and there were quite a few posts on it. Also, I believe there is a tech write-up, if you haven't seen that yet.