Thanks all. I plan to use the cooking guide as just that. A guide. The ultimate indicator for pulling will be "probe tender". I know what that means by reading, but Saturday will be my first real shot at learning it in practice. I was mostly concerned that by putting the brisket it, one of two things (or both) would happen:
1. The brisket would have little chance at turning out decent if the pork was my primary concern.
2. The brisket would prevent me from learning how to cook just a pork butt.
I won't be discouraged by the brisket if it doesn't turn out that great. I am going in to it with the expectation that briskets are much less forgiving than the pork butts. My measure for success on this first cook will be the pork. The brisket is just for extra credit.
Sounds like I can get away with 250, though, and still get some great pulled pork, so I might do that. I think I will also try to get the brisket in a little earlier so that I can get the pit back up to 250 before the pork goes in. That way I'm starting at 250 like I would without the brisket and not building temp (whatever I lose putting the meat in) with both simultaneously.
To the suggestion about spacing, I will have them on different shelves in the Bandera, so I should have plenty of space between them. The pork will be dripping on the brisket and then in to a small drip pan to add back in to both later.
Patience will be available in spades. I'll have a little music playing in the backyard, a fresh bottle of bourbon to sip, and a couple stogies while waiting on the meat. For those reasons, this should be a hobby that I can get in to.
22.5" Weber Kettle / 32" Master Forge Charcoal Grill / Modded/Restored NB Bandera