I am in the middle ( or somewhere in there,,,) of resto on my 70 RR. 383 4sp. I am assuming it is suppose to have colum interlock... but it seems to be missing from my boxes of parts.. I have read they are often removed...?

1st.... what is the funtion and do I need it...

Looks like I can get the complete kit for about $250....


68 Charger 383/ AT Green/Green VT
70 Roadrunner 383/4sp Purple/Black VT