I have a 20' span I need to install an 8" X 8" X 20'3" beam in between. I don't enough room left on the beam for a proper mortis and tennon joint. I do have enough room for a shoulder on each side. It is on the end of the building with no siding and I have full access to the outside and front of the joint. I am considering cutting a shoulder on each side. I was then considering counter sinking a steel plate with holes for a (3) 1/2" thick lag and pulling the shoulder into the beam using a the lag bolts.

I think of it as using a big lag bolt and washer to pull the oak beam into the shoulder. Has anyone succeeded with a repair like this? I was wondering if the building moving with the wind would be enough to loosen the lag bolt?

Picture posting:
Is there a post with instructions on how to do this? I think I need to have the pictures posted on the internet somewhere to allow linking to it. Is there a way to upload the picture into the post directly?