Do a small lip where the butcher block rests on top of the granite and is a different height. That's the most successful way to transition things. Do not attempt to shim the granite to make them the same height.

I don't want the butcher block to be a different height.

The granite is two small pieces on either side of the stove. The rest of the counters are finger-jointed alder strips.

Then run the BB through a surface planer to reduce it's height.

The best functioning installations do have some height difference, in just the manner I described. That allows to not have to have caulk in between the two surfaces which can get kind of grody. The BB can be removed and the joint cleaned if it's done in an overlap method.

My neighbor elevated her granite by using a filler strip around the top of the cabinets. you would not even notice it unless she told you or you were looking for it. I am actually considering doing this as my toe kick needs to be consistent but I would like the total height of the cabinets and granite to be slightly taller as we are all tall in this house. (5'10" and up to 6'5".

Run a rip of appropriate thickness plywood strip (2")at the front and the back of the cabinets to bring the stone up to the top of the BB. (This joint will never stay together, so plan on there being some flex between the two materials) Then run a piece of (matching) base shoe on the face of the cabinets to cover the plywood rip... which should butt nicely into the edge of the BB

Green Designs: What part of "I do not want a height difference" is hard to understand? And the facile advice to "run it through a surface planer" doesn't take into consideration the size of the wood (26 and 40 inches) and the cost of a planer that can handle that width. It's not exactly a home workshop tool.

Footballmom ... do you know what she used? I need 5mm more height (3/16th of an inch). It's going to be tucked back under the granite and can be hidden by a bit of molding if I have to.

Hit up a hardwood lumber dealer nearby and see what size belt sander they have available.

One near me has a 60 inch wide sander.

The alternative it ti block up the shorter pieces and then figure out how to die the blocking used.

There are all sorts of trim strips you should be able to get to match the face of the cabinets.

Plenty of local sawmills or lumber dealers will have a surface planer that will do the job. It's the best option if you want them to be the same height. Doing a trim piece only under the granite will be more visible and awkward than you think unless you have a very dark granite.

Having the two surfaces be the same height has other functional issues, and that's why it's not recommended to do it that way. The difference in expansion rates between wood and granite will mean that the joint between the two will need to be flexible. That means caulk. And caulk isn't the easiest surface to keep clean and sanitized. It also means that if you get the joint too tight, one of the materials will crack.

If its (BB) only 40 inches long, then just have a trim carpenter rip 3/16 off the front faceframe to lower the BB, and run a rabbet on the back/bottom side of the BB that facilitates the back stretcher of the cabinet.. or a notch for the partitions..

Or run a dado 3/16 deep X 7/8 that sits over top of the faceframe if you dont want to cut the faceframe down..

Think lowering the BB, instead of raising the granite..

I would just rip some 3/16" strips of the same material your cabinet face frames are made of, and stain or paint the small edge that shows to match.
rollie's idea works too, but would be a bit more work. I guess it depends if you prefer the higher or lower height overall.

I have a 10 foot counter and an adjacent 6 foot peninsula in the butcher block, and only two tiny sections of the granite, each less than 18" wide. Being practical, it's easier to raise the two small areas than try to modify the already installed 1980s builder grade base cabinets by a smidge.

I finally got a callback from the granite yard - they said if it's not the sink area the most straightforward method is to cut a chunk of tempered 3/16 masonite the size of the cabinet top, glue/nail it down and then install the granite. Stain the edges if needed to hide them.

If, as in my case, the seam is the full depth of the counter, there are small t-shaped moldings from various manufacturers such as Schluter. They come in stainless steel, brass or various colored anodized aluminum finishes. Just tap it into the silicone between the two sections.

I assumed the BB was only 40 inch long, my bad..

If youre only dealing with 18 inch slabs of stone. yes, much easier to deal with raising them. Heck I couldve had it done in less time than Ive spent here offering advise. lol

Luaun plywood happens to be 5.2 mm.

The Results .... I used luan plywood as a full-size shim, covering the top of the two cabinets.

That got the granite within a barely perceptible difference in height and a tarnished brass (for minimal color contrast) t-strip from Schluter covers the gap. It's glued in with bath-quality silicon so it can flex.

So far, no problems.

Photos please.... thanks for updating ; )

I know caulk can get gross, and is not easy to clean. I don't understand why differing heights may be preferred over same height countertops. Won't both of them need caulking? Did anyone figure that out?

"I know caulk can get gross, and is not easy to clean."

Basically impossible to sanitize.

What do you plan on cutting on the butcher block?