There are two completely different front spindles- one for pushbuttons & very early '71s, and one for the rest of us thru '87. The early one has a removable wheel spindle and an integral steering arm and the production one is exactly reversed for those two components.
When you block a person, they can no longer invite you to a private message or post to your profile wall. Replies and comments they make will be collapsed/hidden by default. Finally, you'll never receive email notifications about content they create or likes they designate for your content.
Note: if you proceed, you will no longer be following .