The 3462598 heads were "over the counter" replacement parts, they were not produced when these car were new, so they did not come on AARs or T/As from the factory.
ozrt4406, if you have any regular 340 heads available from 1968-70 you can use them with the normal pushrods and rocker gear. They flow the same and unless you are planning on showing your car with the valve covers off, no will know that you do not have T/A heads.
Barry