Las dos veriones del Bassman http://acruhl.freeshell.org/mga/main/AA864_vs_AB165.html
Effects Loops for a 1970 Super Reverb
Back before '70s Fenders were "vintage", people often modified them to add effects loops. Torres still sells a tube-driven effects loop for the Super Reverb (that involves extensive modification of the amp). So it's possible the one Ruseagle bought was previously butchered, or perhaps he's thinking of butchering it himself (heaven forbid) because he's read so much internet folklore that modulation and delay effects need to go in a loop instead of in front of the amp.
Ruseagle, the reason for using a loop is that adding distortion after time-based effects (reverb, delay, chorus) can sometimes sound muddy, and many modern amps have preamp circuits designed to allow you to add distortion. If you put a time-based effect in front of one of those amps and then crank up the preamp distortion, it's adding distortion to a very complex signal. Loops are after the preamp distortion, so you're modulating a distorted signal rather than distorting a modulated signal.
But a '70 Super Reverb isn't like that. By the time you crank it up enough to add preamp distortion you're also pushing the output tubes hard enough for them to add distortion, which would be after the loop even if the amp had one. Amps like the Mesa Triple Rectifier have very clean output stages and preamps that can generate massive distortion, but a Super Reverb is a completely different beast.
On top of that, distortion before modulation isn't an absolute rule. Sometimes it can sound sort of sterile and controlled, like '80s hair-metal guitarists using massive rack systems.
So like eveyone else said much more succinctly, just put your pedals in front of the amp and experiment with the effects order to find what sounds best to you. You might like having a wah in front of a distortion pedal, or you might prefer having the distortion first -- same with the modulation effects. (If you get head over heels into effects, you might want a Fuzzface in front of a Uni-Vibe into an Octavia then into a wah then into a Marshall-sounding distortion or some other "rule-breaking" arrangement.)