Hey Hotshoe! Thanks for the input...as far as the speedometer, not sure at all since it doesn't work

I'm basing my guesses about RPM on the drive home when I 1st purchased...a friend drove in front of me so I wouldn't get above 50. I'd check in at stops about how fast we were going at our fastet. It just seemed like it wasn't struggling at all or revving high. So...in your opinion what is a good 'shifting strategy'? I know its nerdy but I am not sure about the difference on shifting these old trucks compared to modern manual shifters. 1st gear I shift out of really fast, which 2nd gear seems to want, but I haven't quite figured out 3rd...so you'd downshift to 2nd on a steep grade @ 50 or so?
4 on the floor - The rear cover...um. You mean to the differential? I guess calling and asking the manufacturer about the teeth is a good idea. This sounds dumb but you can just take that cover off w/out problems? And I'll check the shop manual...but I think they are skipping over lots of stuff that they assume any idiot knows. They never met me, clearly.
Ghostrider -- thanks for the link, I'll play w/ that right away.