Eddie's effects, other than the phaser, in the old days (Marshall days) were actually run *after* the amp. Yes, after. How? He ran the amp in to a dummy load, then to the time-based effects (flanger, echoplex and a univox echo) at line level, then to outboard power amps and onward to the speakers, one side wet, one side dry. The the only other thing between the guitar and amp was a frown-faced EQ.
I don't like delay, reverb or echo before overdrive or distortion. It has to be after to work for me. If you want to do the Joe Walsh thing with an Echoplex, running it out front is fine.