Your high speed handling problem could be related to tie rod bushings, steering knuckles, alignment... any suspension component that has to do with wheel alignment.
That said, there are three issues I have to raise:
1) You had no business doing 120mph on the public road. Period.
2) That you did so in a car in disrepair is even worse. You could easily have killed yourself or other innocent motorists.
3) As per the Terms of Service, I ought to lock this thread outright.
Originally Posted by HAN Terms of Service
Conduct: Participants will conduct themselves according to the highest standards of sportsmanship and will maintain a respectful demeanour in their conversations here, and in a manner that will not reflect adversely on the reputation of the board and its management Failure to do so will result in penalties, up to and including the restriction or termination of a member’s right to participate and/or the editing or deletion of a member’s posts, threads or account.
Unlawful activities will not be discussed in the forums. A member may discuss whether a law should exist, but a member may not openly advocate criminal behaviour or disregard for the law.