Just about have all the parts ready to put the 700r4 behind my 261. If anyone has done one of these I would appreciate any informatio you could share on (1) trouble spots; (2) throttle linkage/tvcable; (3) shift linkage using stock steering column (truck has original hydra-matic). Any suggestions?

It will never shift right if you don't get the TVcable PERFECT.
The length of throw measured from the center of the throttle shaft to the cable attach point needs to be exact..... most speed shops sell a MrGasket or B&M carb adapter to do this.

John Kennedy is exactly right. The tv cable geometry has to be perfect. Get a pressure guage and check the tranny pressures before driving the vehicle.
http://www.tvmadeez.com/article/index.php