Here you go dude, as per the Mark IV user manual:
"To duplicate the sounds of our fabled Mark IIC, switches should be set for HARMONICS and TRIODE, with the PRESENCE controls pulled out"
Here's the user manual: http://www.mesaboogie.com/manuals/Mark%204.pdf
From there it depends what kinda tone your after, you can start with:
Treble 7
Bass 2
Middle 4
Drive 7
Gain 8 PULLED
EQ in a V and tweak from there,all depends on what kinda tone, those should give you a heavy Metallica like tone...
"To duplicate the sounds of our fabled Mark IIC, switches should be set for HARMONICS and TRIODE, with the PRESENCE controls pulled out"
Here's the user manual: http://www.mesaboogie.com/manuals/Mark%204.pdf
From there it depends what kinda tone your after, you can start with:
Treble 7
Bass 2
Middle 4
Drive 7
Gain 8 PULLED
EQ in a V and tweak from there,all depends on what kinda tone, those should give you a heavy Metallica like tone...
but i have a little less bass i have a bassist for that 
