On an 84 300D I am the only one that I can remember having an issue getting the lower control arm bolt out.
http://www.peachparts.com/shopforum/diesel-discussion/228951-unexpected-trouble-removing-front-lower-control-arm-bushings.html
The sawsall is frequently used on the upper control arm and you cut through the Arm. On a 84 300D you don't want to cut through the lower control arm and it would be easier to use the Nut spltter to remove the Nut if it is rusted on.
With a sawsall you can only cut the blot because the Lower Control Arm is too expensive and in fact too hard to cut with the sawsall and the mounting points on the Frame for the lower control arm are sheetmetal and could easly be damaged with a sawsall.