to get the 4x4 tunnel in and effectively convert my 2wd cab to a 4x4 cab, I started by laying the weld in half in and marking around it.
then I offset the marker line with tape to make the cut line. also mapped out the front bolt in half.
cut out the rear half and cleaned the bottom of the lip. This was terrible work. I use weld thru primer on the weld in parts lip and the cab side lip to help prevent rust. I'll also seam seal everything later on.
drilled for plug welds and celco'd in the weld in half from the bottom.
welded in. I perfer to TIG the rosette welds so I can heat everything up, fill, then keep the heat on letting it all flow. Also cut front half. I didn't cut front and back out of cab at once to keep as much material in there at all times.
test fit front bolt in piece.
Then I was able to test fit the cab. It fits perfect. I'm very happy. The ride height is a little low for what it'll be final, but its close. and ofcourse the final tires will be bigger.
Where did you get the back half of the 4x4 tunnel?
I need to make my 2wd floor a 4wd so the transmission will fit.