I drill the hole through the frame to 1/2" on both sides and the outside I drill to 7/8" and just weld the sleeve on the outside. I leave the sleeve just a bit long (1/16"ish) so it sticks out of the outside of the frame just a bit. Then I bolt everything up and put short stringer beads to hold it all in place and pull the box back off for finish welding.
![Wink ;)](https://board.marlincrawler.com/Smileys/marlin/wink.gif)