It helps you as the there is more room under the car and between the frame rails. No two piece drive shaft to worry about or small 20 spine PowerGlide output shaft. Your PowerGlide uses the same output yoke as the 700R4. I'm sorry I forgot to mention the TV cable all together. It is important to adjust it correctly as it controls the line pressure applied to the clutches and drums. Out of adjustment and everything burns up in a mater of minutes.
There are actual conversion kits put together by many vendors that will have everything you need with instructions in one box.
Ecklers lists all of the parts starting with a cross-member:
Chevy lock-up pressure switch, 700R4 Transmission:
Turbo Hydra-Matic 700R4 (TH700R4), With Stock Lock-up Torque Converter:
Powerglide To 4-Speed Automatic Transmission Shifter Conversion Kit:
Chevy Transmission To Radiator Metric O-Ring Cooling Line Adapters:
These may not be needed it depends upon the year of the donor transmission. The 700R4 from it's introduction in 1984 was improved annually. The yearly changes made the transmission stronger every year. The newer the better up to the introduction of the 4L60e transmission which is a 700R4 renamed and more importantly computer controlled instead of using the hydraulics in the valve body to shift the tranny. Even some 4L65e parts are still backward compatible with an older 700R4 and high performance transmission shops will rebuild a 700R4 using those parts (even so the Sun Shell is still weak and will snap off if any serious torque such as from a 502 cube BBC is applied).
Detent Bracket, For Cars With Carburetor