I have been told you cannot run without the lockup because your trans will overheat. bowtie overdrive has a very simple kit for about a $100. I havn't got my lockup kit yet but I will be soon and I will let you know how it works. The 700 made a world of difference on my 61 and I havn't even gotten it into 4th gear yet because I dont't have the lockup kit yet.