What would be a good dirt box to get in order to get the fat, saturated distortion tone on songs like Birds by the Butthole Surfers?
Pitchblack - Fulltone Octafuzz - Hardwire OD - Blakemore Effects Deus Ex Machina - MXR Micro Chorus - Diamond Memory Lane Jr - EHX SMMH - Neunaber Wet
it just sounds like a pretty normal medium-high distortion with a little cut mids... i dotn think you need any special things to get it imo.
Can't go wrong with two metal zones on your board

Psyche *Points at sig*

On a serious note, Mayonaise is correct.

AnalogMan Stereo Chorus
Barber Tone Press
Way Huge Supa Puss
or a ProCo RAT
1972 Fender Mustang
2000 Godin SD
Ampeg J20 Jet
Valveking 212
Barber Burn Unit
MXR Smart Gate
BYOC E.S.V. Fuzz
BYOC 10 Band EQ