oldbluetruck,
I bought a $1 fish scale at WalMart and used it as per the instructions in the Shop Manual (1954). It seemed to do the job. I wish I had thought of this years ago - I avoided the steering box because I was afraid to touch it.
There did not seem to be a need to crawl under the truck but my truck is being put back together and everything is clean and all nuts/bults can be loosened/tighented easily.
What you did, sounds OK but I have no opinion as to how well it matches the correct settings (heck, I do not know how well my $1 scale matched the correct settings).
Tim
