Quick rib question.....

Merry Christmas everyone!

I am tossing some ribs on for tonight, and I had a hiccup in my plan. Apparently ribs are popular at Christmas, and I was not able to find babybacks anywhere. I did end up picking up St. Louis spares though. I have only done spares once on the UDS and I foiled them.....tasted great but were too mushy. The past few months I have been doing babybacks, no foil and loving my results. I usually see where my UDS settles (generally 265-275ish)...and they have been coming out at or just under 4 hours perfectly done. Will my current method serve well for these also, or should I plan for shorter time? I am planning to eat at 5, so they will go on very soon here.
Thanks!
Tinman

Thanks guys! I put them on an cranked it up to 300 and then it settled at about 260. I am going to try to keep it up at 275 , which is tough because my UDS loves to park at 260.
I tossed on some ABT's, a naked fatty, and two turkey legs I had on hand; so regardless, we will have protein come 5:00.