Been a few years
 

It has been a few years since I've been on here, but I sold the old truck and picked up another. The one I just picked up a 1978 F250 Ranger Lariat and I want to change the original auto trans out, and put a E4OD in it. I wanted to know if anybody on here has attempted the same thing and if the parts were pulled off a donor vehicle or if you spent the extra money and bought all new parts. Horror stories are more than welcome cause I won't judge. Thanks for the help in advance.

The "E" in E4OD stands for electronic which means it requires certain system components to operate properly.
Among the list are a PCM, TPS,CTS, MLPS,OSS, to name a few. Unless you can provide those inputs to the PCM I don't believe it will work as it should.
PCM-powertrain control module
TPS- throttle position sensor
CTS-coolant temp sensor
MLPS - manual lever position sensor
OSS output speed sensor