If you want to use shift shaft tool on abody vehicle, you will need to lower the tail end of transmission.
May have left out something, but from memory you must remove ground strap from right side of engine, loosen kick down cross shaft, remove transmission cross member and lower transmission. This gives enough room to use tool.
For more details see :
[URL]https://www.forcbodiesonly.com...27-how-to-shift-lever-seal-replacement.45023/[/URL]