Large breed foods are a total rip off, and definately not worth the mark up. Also, Labs aren't really considered large breed, so you'll be just fine with the regular formula in the large bites.
It's always good to have a couple of foods to rotate, too.
ETA: I had good results with Innova foods before going raw.
^^Agree with everything that was said. There really is no difference between a Large Breed formula and a Regular formula if you take a look at the bag. The only difference might be the glucosamine/chondroitin. But that doesn't help much anyway...
Innova Red Meat Large Bites is the same formula as the small bites. The Innova Large Breed Adult (olive green bag with a Great Dane pic) is a totally different formulation than their Innova Adult (darker green bag with a GSD on it, I think!)
Innova Red Meat Large Bites is just formed into a larger kibble for larger mouths!
I think the Innova Red Meat is better than the Innova Large Breed formula...I've used both.
I have 2 older labs 4 and 7. They do prefer the larger kibble versus the smaller kibble. Where as my other 2 dogs ori~pei he will eat any size kibble he has no prefrence and my beagle senior dog does prefer small. Labs are a medium to large compact breed.
And I agree with all here you can just get the bigger kibble and its fine!