Hi Chris,
First, this thread belongs to General Discussion or Connections and Routing, I guess. Second, you should explain in some more detail
what you want to do before you ask how to achieve it...
You want the Mesa to drive your dry cab(s), I suppose, and the 8008 to power your wet cabs. Soooo.
1) Git-Axe front input.
2) In the grid: possible pre-preamp fx first, then into an amp block, then split your path in two, one to the fx loop block, the other to your wet fx. Those should all be 100% mix, level to taste, maybe in parallel, maybe in series, whatever, ending in the main output right in the grid diagram.
3) Fx loop block sends to out2, which should be connected to your dry amp (the Mesa).
4) Wet path ends at out1, which should go to your Marshall (wet cabs).
Never tried this, usual disclaimers apply, have fun.
Ingo