What's wrong with a powerglide and a L6?
My limited experience opinion is that you must choose between stand-still acceleration and comfortable highway cruising. Since the PG only has two gears your engine really gets worked with a 4.11 posi rear on the interstate.
On the other hand with a 2.73 gear you can cruise all day long at 75-80 - no problems. But your off-the-line acceleration will suffer.
The 700R4 fixes this compromise; and gives you the best of both worlds. There are several other GM transmissions that do the same (T5, T56, 89MM).
-magic mike-
