SM420 to 700R4 conversion, which torque converter to use????

[naystcb]

I could use some help, I am swapping out the SM420 on my 1971 Cheyenne Longhorn C-20 with a 700R4. My truck has a 396 and has 4.57 gears. I have two torque converters that I can use and need to know which would be the better choice for performance if any. One is a DG5F and the other is a DE6F. Also, has anyone done a swap like this before and if so do you have a conversion build list or guide available that I can go by. Thanks.