Hi HTC... was born/raised in Oregon
but not the point of my post. Some thoughts on the subject until Rainee gets here.
I've successfully "Q'ed" babybacks on a Weber three burner gasser successfully. I found babybacks to be much more tender naturally than "normal" spareribs, and do okay at 275 and maybe even 300.. but 300 might be pushing it. Low/Slow is the key to pork and ribs can get dry and stay tough if cooked to hot/fast.
Andy is spot on when he says they need 2-3 hours.. actually I think 4 hours might be necessary... but not all ribs, babyback or otherwise, are created equal.. so you have to check by attempting to bend your rack in half or whatever.. if you can split your rack by bending, they are done. Start checking at about 2 1/2 to 3 hours or a six-pack's worth.. which ever comes first.
On my gas grill, which I gave to my son, I could get 275 with one burner on (the other two off).. and would toss a foil pack of wood chips (your choice.. I used hickory I think).. poke a couple of holes in the to of the foil.
One thing that would also help, although I don't do it now 'cause I use very low/slow charcoal for my ribs.. is to brine them... maybe 1/4 cup sugar, 1/4 cup table salt (or 1/2 cup kosher) in about 2 quarts of water (I estimate).. toss in the refrig for 6 or more hours...
Then use a rub...
this is one idea but there are a bunch of recipes.. probably on this site and on the net:
1 tablespoon plus 1/2 teaspoon sweet paprika
1 1/2 teaspoons chili powder
1 3/4 teaspoons ground cumin
1 1/2 teaspoons dark brown sugar
3/4 teaspoon table salt or 1 1/2 teaspoons kosher salt
3/4 teaspoon dried oregano
3/4 teaspoon ground black pepper
1 teaspoon ground white pepper
1/2 teaspoon cayenne pepper
Wrap in saran or other wrap... refrig 6-8 hours or overnight.. the longer the more "spicy" they will be.
Stick your probe (Polder or other.. I use a Maverick remote) in a raw potato with the end sticking out 2 inches or so... set it beside your ribs... that way you can measure you actual grill temperature.. Depending on your gas grill, if your temp is still too high...you might have to prop your lid open 1/4" or so with a wood chip or something..... then watch the temp and be sure it doesn't drop below 200 degrees...