LMC lists those for '67 and up, so you would likely have to modify them to work on your '64. I think that if you have the means to perform the necessary work, you can make your own for less than $100. You can get 3/8" rod ends from Summit for $5.00 each. They are made by QA1.
http://www.summitracing.com/parts/sum-msf6