"I do more small group than whole group.  My small group is differentiated (highest group and second highest group are doing things outside of the core because they are already proficient, third group is my "on level core kids" who are doing just core reading practice, and low group is doing core with me in small group, core with an assistant during the "independent" time for most kids, and intervention outside the block).  The high kids are staying "high" because I'm spending all the time needed to "find and use" materials that are challenging and that teach them the skills they are ready to learn outside the core. 

For whole group, the high kids are more interested than I thought they would be in the "easy" stories.  I do a lot of "cross group" reading during small group time.  High kids read higher texts as a "practice" to others in other groups, lower and at level kids are reading "on level" texts to the higher kids....

I've taught them all how to "work independently" so they are spending a LOT of time reading and working independently when it's not time for their group (daily 5 type routines... but modified to fit my needs).  The only kids who barely have any independent time are those that are the lowest.... those kids go from whole group, small group with an assistant, small group with me, and a little bit of time independent at the end.

I'm also doing a lot of reading to them from other things.  Reading texts that are "connections" to other texts and taking time to discuss connections and make them as well as working a lot on vocabulary aspects of reading in whole group.  Lots of partner sharing (ELD style), lots of varied ways to have them practice comprehension skills too besides worksheets (sometimes we do story maps, sometimes we do a book project where they have to put the characters on one page, setting on another, writing a summary on another page, etc....) during independent time (this is particularly good for the high kids, but everyone seems to be benefiting.  I do a LOT of extra added comprehension (first grade is "light" on comprehension, in my opinion, and there's a lot of places to add in additional comprehension.)

Basically, I look at what they need (like I always have) and just give them that.  The difference is, I don't "go up the core" anymore.  I have to chase down other books to use and find other materials for those high kids (which takes a lot of time).  The difference is not "what" I'm doing, it's "how" I'm doing it and trying to make sure I'm following the protocols to the best of my ability, and still do what's best for each individual child."