Which loop shoud I put my Boss GT8 in? I'm aware of the 4 cable method of connecting it so that the Wah and Volume Stays in front of the preamp, but I want the Delays, etc inthe loop
If you're just using time based effects (chorus, reverb, delay, etc), the parallel loop should work fine and will theoretically result in the least degradation to your amp's true tone and punch.
If you also want to use EQ & noise reduction, however, you will have to run everything through the serial loop for these effects to work properly.