Car won't run past 60mph

So far I confirmed that I do not have 2.76 gears, I have the 2.93 gears close enough. Says the stamped ring gear. So I added some fresh fluid to the diff and ruled out that its not the gear ratio keeping me from going past 71mph in third gear at 4,000 rpm. It would have been nice to see 3.91's on the ring gear that would have made more sense. So I bought a filter and ATF+4. Next is to drop the trans pan check things out and adjust the band's and see if that makes any difference at all. I also have the common kickdown lever shaft leak. Is it a pain to remove the valve body to change the gaskets on the kickdown shaft?