http://purplesagetradingpost.com/sumner/techinfo/700R4p1.html

http://www.transmissioncenter.net/speedometer_calibration_______va.htm

http://www.bowtieoverdrives.com/index.shtml

http://www.tciauto.com/Products/Instructions/instructions/gm_tv_cable_adjust.htm

Here are a few site I have read and used as I plan on putting a th700r4 in my '57 Suburban. The 4l60 is a th700r4 with a new name; a 4l60E is the same trans but with more elctronics in it, as you probably know! Just make sure you know which one you have.
Bowtie Overdrives has a kit that does not use a vaccuum switch for the lock up converter and a lot of infos and parts.
TV cable is very important to set up properly, but not very difficlut using stock GM cable, especially if using a GM carb or throttle body with the bracket on it.
Easy to switch the trans to a cable driven speedo (with junkyard parts), you can find the right gears to make your speedo accurate.
These site should get you started!

'57 Chevy Suburban; '70 Chevy Impala.